57180509 caesar ii training
TRANSCRIPT
CAESAR II 5.1 Training
Vivek Paul Engineer (Tech.) KLG SYSTEL LTD
AGENDA
Introduction to CAESAR II & Basic theories Data Inputting Usage of various spread sheets Modeling of piping system
Modeling Miters Reducers
Nozzle/Vessel Junction through C-nodes Rigid Elements Bellows Cold Springs Expansion Loop Hangers Static analysis along with wind loads Combining Load Cases as per codes Various Graphics Outputs Isometric generation Combining Dynamic Load as per code requirement Creating various reports (WRC 297, Loads on pumps compressors, Exchangers) Processing the result
Introduction to Pipe stress analysisIn order to properly design a piping system, the engineer must understand both a system behavior under potential loading as well as the regulatory requirements imposed upon it by governing codes. System behavior can be quantified through the aggregate values of numerous physical parameter like acceleration, velocities, displacements, internal forces and moments, stress, and external reaction developed, under applied loads. Allowable value for each of them are set after review of appropriate failure criteria for the system. System response and failure criteria are dependent on type of loading which can be classified by Primary Vs Secondary, Sustained Vs Occasional, Static Vs Dynamic.
Why do we perform Pipe Stress Analysis
In Order to Keep stress in the Pipe & Fittings within code allowable levels. In Order to keep Nozzle loading on attached equipment with in allowable of manufactures or recognized standard (NEMA SM23, API610, API617) In Order to calculate design loads for sizing supports and restraints. In order to determine piping displacement for interference checks In order to solve dynamic problems in piping, such as those due to mechanical vibration, fluid hammer, pulsation, transient flow and relief valve discharge In order to help optimize piping design.
Pipe Stress Design DataDesign Data typically required for pipe stress analysis consist of Pipe Material & Size Operating Parameter Temperature Pressure Fluid Contains Code Stress Allowable Loading Parameters Insulation Weight External Equipment Movement Wind & Earthquake criteria
But we can go ahead only when you know this
Basic Piping Isometric reading & Generation Piping components
CAESAR II Main Menu
After starting CAESAR II Main Menu appears, it is recommended to kept this Window minimum as this will used only for accessing toolbar and command
File Menu
Set Default Data Directory Tool to set Default project directory where all the files of particular projects will be saved. Selection of data directory is very important as configuration, units, data files found in the directory will be considered to be a Local to that Job New For creating a new Piping or structural files Open Open an existing piping or structural Job Clean up (Delete) Files Enables user to delete unwanted scratch, listing, input or output files to retain more hard disk space Recent Piping or Recent structural Files Display the four most recently used Piping or structural files Exit Closes CAESAR II Application
Input Menu
Piping
Inputs CAESAR II Piping Model Converts Existing Piping Model to buried piping
Underground
Structural Steel
Input CAESAR II Structural Model
Piping Input
Data Fields
Node Numbers Element Lengths Element Direction Cosines Pipe Section Properties Operating Conditions: Temperature & Pressure Special Element Information Boundary Conditions Loading Conditions Piping Material Material Elastic Properties Densities
Spreadsheet Overview
Undo/Redo Customize Toolbar
Necessity of Node PointsNode points are required at any location where it is necessary to provide information to, or obtain information from pipe stress software. Node points are required to: Define geometry
System Start, End, Direction Changes, Intersection etc System start, isolation or pressure reduction valve Change in pipe cross section or material, rigid element or expansion Joints Restraints and imposed displacements Refinement of mass modal Insulation Weight Imposed Forces Earthquake g-factor Response spectra Wind Exposure & Snow Stress at piping mid spans Displacements at wall penetration
Observing Changes in operating condition
Define element stiffness parameters
Defining Boundary conditions
Specify Mass points
Note Loading condition
Retrieve information from the stress analysis
Node NumbersThe FROM & TO node number defines the starting & end of the element respectively. Node numbers must be numeric, ranging from 1 to 32000. Normally, the FROM node number is "duplicated forward" by CAESAR II from the preceding element
NAMEThis check box is used to assign non-numeric names to node points. Double-clicking this check box activates an auxiliary spreadsheet where names, of up to 10 characters, can be assigned to the FROM and/or TO nodes. These names will show up in place of the node numbers in graphic plots and reports
ELEMENT LENGTHLength of element is entered as a delta dimension which are the measurement along X, Y and Z axis. one or more entries must be made except Zero length Expansion Joints.Note: 3-2, -2, 2-3-3/16 are the acceptable format for Feet & Inches Entries. Simple forms of addition, multiplication, and division may be used as well as exponential format.
Please Answer
6.3 6-10 6-10-1/4 6-10-1/4+3-7 6.3*12
=? =? =? =? =?
ELEMENT DIRECTION COSINE
Direction Vector or direction cosine which define the center line of the element.
ELEMENT OFFSET
Thermal expansion will be 0 for the offset portion of an element. No element flexibility will be generated for offset part at the time of analysis.
PIPE SECTION DATA
Diameter Wt / Sch +Mill Tol %; WI -Mill Tol % Seam-Welded Corrosion Insul Thk
DIAMETER
The Diameter field is used to specify the pipe diameter. Normally, the nominal diameter is entered, and CAESAR II converts it to the actual outer diameter necessary for the analysis. There are two ways to prevent this conversion: use a modified UNITS file with the Nominal Pipe Schedules turned off, or enter diameters whose values are off slightly from a nominal size (in English units the tolerance on diameter is 0.04 in.)
ANSI Nominal Pipe ODs, in inches (file ap. bin) 1 1 2 2 3 3 4 5 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 42 JIS Nominal Pipe ODs, in millimeters (file jp. bin) 15 20 25 32 40 50 65 80 90 100 125 150 200 250 300 350 400 450 500 550 600 650 DIN Nominal Pipe ODs, in millimeters (file dp. bin) 15 20 25 32 40 50 65 80 100 125 150 200 250 300 350 400 500 600 700 800 900 1000 1200 1400 1600 1800 2000 2200
Wt / Scht =t+cm
t = minimum wall thickness, in. t = minimum wall thickness required for pressure, in C= sum of allowances for thread or groove depth, corrosion, erosion and manufacturers tolerance, inm
Wt / SchThe Wall Thickness/Schedule field is used to specify the thickness of the pipe. Normal input consists of a schedule indicator (such as S, XS, or 40), which will be converted to the proper wall thickness by CAESAR II. If actual thickness is entered, CAESAR II will accept it as entered. Available schedule indicators are determined by the active piping specification, set via the configuration program. The available schedules are listed below.
ANSI B36.10 Steel Nominal Wall Thickness Designation:
S - Standard XS - Extra Strong XXS - Double Extra Strong
ANSI B36.10 Steel Pipe Numbers: 10 20 30 40 60 80 100 120 140 160 ANSI B36.19 Stainless Steel Schedules: 5S 10S 40S 80S JIS PIPE SCHEDULES
1990 Steel Schedules: 1990 Stainless Steel Schedules:
10 20 30 40 60 80 100 120 140 160
5S 10S 40S DIN PIPE SCHEDULES
+Mill Tol %; WlThe Positive Mill Tolerance is only enabled when IGE/TD/12 is active, and is used when the Base Stress/Flexibility On directive of the Special Execution Options is set to Plus Mill Tolerance. In that case, piping stiffness and section modulus is based on the nominal wall thickness, increased by this percentage. The user may change this value on an element-byelement basis.
If the B31.3 piping code is activated, this field is used to specify the "weld strength reduction factor" (Wl), to be used in the minimum wall calculation for straight pipe.
-Mill Tol %The Negative Mill Tolerance is read in from the configuration file for use in minimum wall thickness calculations. Also, for IGE/TD/12, this value is used when the Base Stress/Flexibility On directive of the Special Execution Options is set to Plus Mill Tolerance. In that case, piping stiffness and section modulus is based on the nominal wall thickness, decreased by this percentage. The user may change this value on an element-by-element basis.
SEAM-WELDEDIf the B31.3 piping code is active, the "seamwelded" check box is used to activate the Wl field. The Wl field is the "weld strength reduction factor" used to determine the minimum wall thickness of the element.
CORROSIONEnter the corrosion allowance to be used order to calculate a reduced section modulus. A "setup file" directive is available to consider all stress cases as corroded
Insul Thk (*)Enter the thickness of the insulation to be applied to the piping. Insulation applied to the outside of the pipe will be included in the dead weight of the system, and in the projected pipe area used for wind load computations. If a negative value is entered for the insulation thickness, the program will model refractory lined pipe. The thickness will be assumed to be the thickness of the refractory, inside the pipe.
OPERATING CONDITION
Temperature Pressure
TEMPERATURECAESAR II uses these temperatures to obtain the thermal strain and allowable stresses for the element from the Material Database. Thermal strain can be specified directly as well. thermal strain have absolute values on the order of 0.002 and are unit less. CAESAR II uses an ambient temperature of 70 F, unless changed using the special execution parameter option. There are nine temperature fields, to allow up to nine different operating cases. Temperature values are checked (by the error checker) to insure they are within the code allowed ranges. Users can exceed the code ranges by entering the expansion coefficient in the temperature field in units of length/length. The expansion coefficient can be a useful method of modeling cold spring effects. Also when material 21(userdefined material) enter temperature *expansion coefficient as in the example below. Values entered in the temperature field whose absolute values are less than the Alpha Tolerance are taken to be thermal expansion coefficients, where the Alpha Tolerance is a configuration file parameter and is taken to be 0.05 by default. For example, if the user wanted to enter the thermal expansion coefficient equivalent to 11.37in./100ft., the calculation would be: 11.37in./100ft. * 1 ft./ 12in. = .009475 in./in.
This would be entered into the appropriate Temperature field.
PRESSUREThere are ten pressure fields, to allow up to nine operating, and one hydro test, pressure cases. When multiple pressures are entered, the user should be particularly careful with the set up of the analysis load cases, and should inspect CAESAR II's recommendations carefully before proceeding. Access to operating pressures 3 through 9 is granted through the Extended Operating Conditions input screen, accessible via the Ellipses Dots button directly to the right of the standard Temperature and Pressure input fields. This dialog box may be retained open or closed at the convenience of the user. Entering a value in the Hydro Press field signals CAESAR II to recommend a Hydro test load case.
COMPONENT INFORMATION
Bend Rigid Element Expansion Joint Reducer SIF & Tees
BendIf element described by input sheet ends with bend, elbow, mitered joint bend check box to be checked.
Bend angle is always defined by element entering and leaving the bend. By default the bend radius (Basically it is long radius) is 1.5 times of Pipe nominal diameter. CAESAR II automatically creates two nodes on bend at 0 degree location and bend mid point. (Bend) TO node of the element entering the bend located at far point on the bend. This is for stress and displacement output. Far point is the weld line of bend and adjacent to element leaving the bend. 0 degree Node will not be created if Total length of element specified is equal to R
tan( /2) Nodes on bend curvature can not be place closer together then specified angle in CONFIG/SETUP File. Minimum and Maximum bend angle also need to be specified in CONFIG/SETUP File only.
BEND- TYPEFor most codes, this refers to the number of attached flanges, and can be selected from the drop list. If there are no flanges on the bend then leave the Type field blank. It has been seen that elbows tends to ovalize during bending.
Single & Double flanged bends can be enter by entering 1 or 2 respectively for the type. When specifying single flanged bends it does not matter which end of bend the flange is installed If user wants to include the weight of rigid flange then he has to put rigid element with equal length of flange on desired side of bend.
Some practice
45 degree elbow U type/180 return bend Circular ring
Mitered BendsA Miter Joint is a change in pipe direction through proper cutting and welding of straight pipe.
Closely Spaced Widely Spaced
R = r[1 + cot ] 2
FITTING THICKNESS
Thickness of the bend will be changed without affecting preceding & following pipe CAESAR applies this change on current bend only As per B31 Stress at elbow are calculated on basis of section modulus of matching pipe however the stress intensification factor & Flexibility factor for bend is based on wall thickness of elbow.
K-FACTORK-Factor shows flexibility of bend w.r.t same length of pipe. If K-factor value is 1.5, it means bend is 1.5 times as flexible as same length of pipe. Bend flexibility factor are calculated as per code but user can overwrite it.
RESTRAINTSRestraints we are using to provide boundary condition. Anchor Double Acting & Single Acting Transitional/Rotational Guide LIM XSNB, YSNB, ZSNB X2, Y2, Z2 K2 XSPR, YSPR, ZSPR X (cosx, cosy, cosz) or X (vecx, vecy, vecz) RX (cosx, cosy, cosz) or RX (vecx, vecy, vecz) XROD, YROD, ZROD
ANCHORSAnchors is an rigid element hence displace should not be defined at an anchor node. For anchors with displacement following point should be considered Enter only displacement for the node Do not apply any restraint or anchors at the node to be displaced All 6 degree of freedom at the node should be defined. Leaving the displacement field blank will default to zero.
DOUBLE ACTING RESTRAINT
Transitional Rotational
SINGLE ACTING RESTRAINT
Always gives information about Free Axis Can be defined along +ve, -ve & skewed axis If CNode left blank then the restrained node is connected via the restraint stiffness to a rigid point in space. If the CNode is entered then the restrained node is connected via the restrained stiffness to the connecting node
GUIDE Double Acting
Guided pipe in the horizontal or skewed direction will have a single restraint, acting in the horizontal plane, orthogonal to the axis of the pipe. A guided vertical pipe will have both X & Z direction supports
DIRECTIONAL LIMIT STOPSLimit stops are single pr double acting restraint whose line of action is along the axis of the pipe, these restraint can have gaps which permits free movement along the restraint line of action.
Directional Limit stop with gap Two limit stops acting in opposite direction
WINDOW
Equal leg windows are modeled using two double-acting restraints with gaps orthogonal to the pipe axis Unequal leg windows are modeled using four single-acting restraints with orthogonal to the pipe axis
ROTATIONAL DIRECTIONAL RESTRAINT These restraints can be considered specialty items and are typically only used in sophisticated expansion joints or hinge models.
Bidirectional rotational restraint with Gap Hinged Assembly with directional rotational restraint
Single-Directional restraint with predefined displacement
Single-Directional restraint and Guide with Gap and Predefined Displacement
RESTRAINT ON BEND AT 45 DEGREES
RESTRAINT ON BEND AT 30 & 60 DEG
Vertical Dummy Leg On Bends
Reducer
Load Case Editor
Scale Factor for load componentsWhen building load cases, load components (W,T1,D1,WIND1 etc.) may be preceded by scale factors such as 2.0, -, 0.5 etc.One loading is multiple of other Loading may be directionally reversible (i.e. wind or earthquake), + & - will be used to specifydirection 1.5W+1.1T1+1.1D1+1.25Wind1
User defined load case names
Note: Load case name should not exceed 132 characters
User-controlled combination methods
Algebraic Scalar SRSS Abs Max Min Sign Max Sign Min
AlgebraicThis method combines the displacement, forces, moments, restraint loads and pressures of the designated load cases in an algebraic (vectorial) manner. The resultant forces, moments, and pressures are then used (along with the SIFs and element cross-sectional parameters) to calculate the piping stresses. New combination cases automatically default to this method, unless specifically designated by user.
SCALARThis method combines the displacement, forces, moments, restraint loads and stresses of the designated load cases in a scalar manner but retaining consideration of sign. This method might typically be used when adding plus or minus seismic loads to an operating case, or when doing an occasional stress code check.
SRSSThis method combines the displacements, forces, moments, restraint loads and stresses of defined load cases in Square root of the sum of the squares manner; however due to squaring -ve vs. +ve values yield no difference. This load typically used when combining seismic loads acting in orthogonal directions.
AbsThis method combines the displacements, forces, moments, restraint loads and stresses of defined load cases in Absolute manner; however due absolute values used by the combination method ve & +ve values yield no difference in the results. This load typically used when combining loads acting in orthogonal directions. This method may be used when doing an occasional stress code check (i.e. absolute summation of the sustained and occasional stresses)
MAXFor each result value, this method selects the displacement, force, moments, restraints load, and stress having the largest absolute value from the designated load cases; so no actual combination, per se, takes place. Load case results are multiplied by any scale factor prior to doing the selection of MAXIMA. This method is typically used when design case (worst loads, stress etc.) from number of loads.
MINFor each result value, this method selects the displacement, force, moments, restraints load, and stress having the smallest absolute value from the designated load cases; so no actual combination, per se, takes place. Load case results are multiplied by any scale factor prior to doing the selection of MINIMA.
Sign MAXFor each result value, this method selects the displacement, force, moments, restraints load, and stress having the largest actual value considering the sign from the designated load cases; so no actual combination, per se, takes place. Load case results are multiplied by any scale factor prior to doing the selection of MAXIMA. This method is typically used in conjunction with the SignMin method to find the design range for each value (i.e. maximum positive and maximum negative restraint loads)
SignMinFor each result value, this method selects the displacement, force, moments, restraints load, and stress having the Smallest actual value considering the sign from the designated load cases; so no actual combination, per se, takes place. Load case results are multiplied by any scale factor prior to doing the selection of MAXIMA. This method is typically used in conjunction with the SignMax method to find the design range for each value (i.e. maximum positive and maximum negative restraint loads)