overview of the maestro system · 2010-09-16 · overview of the maestro system 1 maestro 2010 ....

www.maestromarine.com

Overview of the MAESTRO System

1 MAESTRO 2010

www.maestromarine.com MAESTRO 2010 2

Historical Highlights

Early Stages of Development and Fielding Professor Owen Hughes conceived and developed MAESTRO Wrote and published (Wylie/SNAME) textbook Ship Structural Design 1982 – 1983 Began moving MAESTRO into user community

Initial Cycle of Distribution, 1983 – 1989

Navies: United States, The Netherlands, The United Kingdom Commercial design organizations

Middle Period of Distribution, 1990 - 1999

Navies – total of 16 including Canada, Australia, Germany Ship Classification Societies – American Bureau of Shipping, Lloyds Register,

Bureau Veritas, China Class, Croatian Register of Shipping Commercial User Base – expanded to 40-50 companies University Licenses – 20+ universities worldwide

Recent Highlights, 2000 - 2010

Continued distribution throughout commercial industry Established links with Professor Jeom Paik and ALPS limit states analyses Expanded to handle larger models, faster, with improved solvers


What is MAESTRO?

Beam Coarse Mesh Full-Ship Detail Full-Ship

www.maestromarine.com MAESTRO Academic Conference 2010 4

Rationally-based Structural Design

“design directly and entirely based on structural theory and computer-based methods of structural analysis and optimization to achieve an optimum structure based on a designer-selected measure of merit.” “A true design process must be capable of accepting an objective, of actively moving towards it, and of achieving it to the fullest extent possible.”


Main Capabilities

MAESTRO is a complete ship structural design system.

Global Design Analysis • Rapid Structural Modeling • Ship-based Loading • Finite Element Analysis • Structural Failure Evaluation • Structural Scantling

Optimization • Hull Girder Ultimate Strength • Natural Frequency • Corrosion

Local Design Analysis • Integrated Coarse Mesh/Fine

mesh Analysis • 3rd Party Import/Export • Automated Global BCs

3rd Party Data Exchange • Hydrodynamic Load Interface • Import/Export Nastran Data • Geometry Import


Structural Modeling

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• Ship hull consists of a series of segments: cargo holds, compartments • FEMs are large and complex, and construction should be done in a carefully planned

levels and sequences • Modules are helpful as they are ideal high-level building blocks


The MAESTRO “Module”

Modeling Components Reference/Opposite Ends

Section Spacing/Number

Endpoints

Frames, Girders, & Strakes

Stiffener Layout/Spacing


Ship Hull Girder Properties

Basic Ship Structural Properties Hull girder properties, e.g.

Inertias, Cross-sectional Area, Neutral Axis, Section Modulus, etc., can be recovered from the model.

Longitudinal Effectiveness On/Off


Ship Based Loading

Lightship mass distribution Structural weight Weight distribution

Hydrostatic Loads Still water Waves

Tank Loads External bending moment and

shear force Cargo Masses

Forces Moments

Accelerations (6 d.o.f.) Pressure Loads Mass/Inertia Based Loads Hydrodynamic Loads


Ship-based Loading


Finite Element Analysis

Obtain the stresses throughout the model for all defined load cases.


Structural Failure Evaluation (Limit States)

Evaluation Types

MAESTRO

ALPS/ULSAP

ALPS/HULL

Evaluate the entire ship for all of the different possible failure modes for each load case.



Limit State Analysis The formulation of MAESTRO’s limit states is covered in Ship Structural Analysis and

Design and Ultimate Limit State Design of Steel-Plated Structures

These constitute the theoretical manual for MAESTRO’s limit state



Evaluation is automatic - all structural members are evaluated to the factors of safety chosen by the user

Different factors of safety can be specified for all “collapse” limit states and for all “serviceability” limit states, or specified on a limit state-by-limit state basis.

In addition to the strakes, frames, and girders which receive full evaluation... Additional panels, triangles, and additional beams receive limited evaluation

Struts and pillars are evaluated for Euler buckling

Evaluation Patches



MAESTRO Adequacy Parameters ALPS/ULSAP Adequacy Parameters



Automatic Evaluation Patch (Panel) Generation

A patch is a collection of elements with its boundary supported by bulkheads or beams.



Collects plate and beam elements

Automatic (or Manual) Evaluation Patch Generation

Represents the stiffened panels and correct panel parameters


Hull Girder Ultimate Strength

ALPS/HULL, 2D (available now)

ALPS/HULL, 3D (near term implementation)


Optimization

Uses sequential linear programing (SLIP2)

Optimization eliminates any structural inadequacies

While achieving user-specified objectives Least Weight

Least Cost

Weighted combination

Rationally-based Design Process (Optimization) Iterates structure through design cycles to

revise scantlings

Re-runs the finite element analysis

Re-evaluates the structural adequacy of each member for all failure modes and load cases

Process continues unit the structure has converged to an optimum design that has no structural inadequacies

“SLIP2 is able to solve problems involving a large number of constraints of various types and in which the objective may be any user-specified non-linear function of the design variables.”

Co

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nit

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Cycles


Rationally-based Structural Design

1 CONSTRUCTION OF THE FINITE ELEMENT MODEL

FINITE ELEMENT ANALYSIS Calculate Load Effect (Q)

LIMIT STATE ANALYSIS Calculate Limit Values of

Load Effects (QL)

OPTIMIZATION OBJECTIVE

DESIGN EVALUATION Constraints satisfied? Objectives achieved?

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SPECIFICATION OF LOADS, LOAD PARAMETERS, AND DESIGN WAVES

FORMULATE CONSTRAINTS

g1 g2 g3 Q QL


Fine Mesh Analysis

Fully integrated fine mesh modeling and analysis capability. Ability to import FEMAP/NASTRAN detailed models.


Fine Mesh Analysis

MAESTRO Embedded Analysis Integrated local models into the global model

through Rspline elements

Solve coarse mesh model and fine mesh models

MAESTRO Top-Down Analysis Multiple models in a region

(1) solve coarse mesh model, (2) impose coarse mesh model nodal displacements as boundary conditions, (3) solve fine mesh models

3rd Party Top-Down Analysis Export fine mesh models with boundary conditions


Natural Frequency Analysis

Perform a natural frequency analysis with or without added mass


Corrosion

Corrosion is defined as an additive property to the original structure

Associated via a Load Case

Net thickness is automatically used in FEA and Limit State Analysis


3rd Party Data Exchange

Hydrodynamic Code Interface, such as PreCal, Wamit, VERES, Lamp, Mora, etc.


3rd Party Data Exchange

Import/Export Nastran Data


MAESTRO Benefits

Easy to create, modify, and maintain coarse mesh model

Ship based loading

Tanks

Hydrostatics

Hydrodynamic Interface

Structural Panel Evaluation Paradigm

Integrated & Switchable Structural Criteria

Coarse mesh / Fine mesh coexistence


Contact US

DRS Defense Solutions, LLC

Advanced Marine Technology Center (AMTC)

Stevensville, MD 21666

Phone: 410-604-8006

Fax: 410-643-5370

Email: [email protected]

Web: www.maestromarine.com

mailto:[email protected]

http://www.maestromarine.com/

overview of the maestro system · 2010-09-16 · overview of the maestro system 1 maestro 2010 ....

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