lms virtual.lab – the unified environment for … virtual.lab motion lms virtual.lab motion auto...

1 copyright LMS International - 2007

LMS SCADASMobile - Lab

LMS Virtual.Lab – The Unified Environmentfor Functional Performance Engineering

LMS Test.Lab LMS Virtual.LabMotion, NVH, Acostics, OptimizationLMS

Tec.Manager

LMS Engineering and Deployment Services

Technology TransferProcess Transformation

& Best Practices System Support

LMS Imagine.Lab OPTIMUSLMS OPTIMUS


Strategy and Assumptions

CAD Data could have come from UGS, Pro-E, Solidworks, Autodesk, ParasolidsInterface with all FEA Tools, ABAQUS, NASTRAN, ANSYS, UGS - NX, PERMAS, or CATIA GPSModeled using a Scalable Approach without having to switch between different products.

Reasonably accurate results for early trade off studies vs. high accuracy for test correlationProvide option to choose between Medium Fidelity / Fast Solution vs. High Fidelity / Accuracy Leverage capabilities of the Virtual Lab Framework, Knowledgeware, Design Tables, Parameterization etc.

Highlight the techniques that can be used with Virtual Lab for support of a typicalPreliminary Design Decision Process.


Process Flow – Drop Test

Tool for modeling and simulation of multi-disciplinary systems (hydraulic, pneumatic, thermal, mechanical, controls, etc.) Design of Oleo System1-D Representation of Landing Gear

Tool for 3-D Multi Body system designValidate Oleo system with 3-D Landing Gear Model and Flexible Modeling for Critical Components

Reuse AMESim Oleo System Model

Tool for FEA of ComponentsProvides Craig-Bampton modes for Flexible Bodies

LMS Virtual.Lab MotionLMS Virtual.Lab Motion

LMS Virtual.Lab MotionLMS Virtual.Lab MotionAuto FlexAuto Flex


Drop Test Model – Oleo Dynamics

Starting Point :1D AMESim Model of Landing GearInitial Design of Oleo Damping

Validation:1D AMESim Model Oleo Hydraulics Reused by 3-D Motion Drop Test Simulation

Motion/Plant AMESim – “Coupled Equations”Motion Solver Integrates both sets of Equations


*V_

α*

belt

wheel plane

ϕ*

ϕ γ

αV_c

C

residual springs

ΩV

z

Fx

wheel rim belt

Fz

effw

reff

eff. road plane actual road surface

Fy

Mzeffβ

ψ.

-

pac 2004

SWIFT model structure

Drop Test Model – Tire & Lift Forces

Tire ForcesCalculates & Applies forces at the tire contact patch between ground and wheel body in up to 3

directions when in contactChoice of tire model typically a trade off

• Level of accuracy required• Amount of test data available• Desired run times

Full library of tire forces available in Virtual.Lab Motion• Simple Tire• LMS Durability Tire• TNO – Swift Tire • Standard Tire Interface ( User Defined Tire)

Based on data provided & goals of the process, Simple Tire force was usedLift Force

3 Point force applied to aircraft in global z direction equal to total weight of aircraft + gearAircraft weight is parameter to this force


Drop Test Model – Contact Forces

Large gaps present in Lug – Drag & Side Braces

Added to drop test model but required for Stress analysis portion

Virtual.Lab motion Contact forces used to simulate these gaps

Based on Hertzian formulation, very stable, fast & accurate


Drop Test Model - Flexibility

FEA required to calculate mode shapes as inputTough choice about which FEA solver to use

Virtual.Lab Motion is compatible with a number of different solversCan “reuse” models between Drop Test &

Stress Analysis with any of these solversCraig-Bampton mode set drivers available

CATIA GPS chosen because of Auto Flex capability

Easiest setup of Flexible BodiesFully Associative with geometrySelect Rigid Body in mechanism model

the Mesh & FE load cases are automatically defined

2nd Craig-Bamption mode – 106Hz


Drop Test Results


Drop Test Load Stroke curves

Load

-po

unds

Stroke - inches


Process Flow – Stress Analysis

Reuse Flexible Drop Test model to generate BC for stress analysisDesign Tables & Configurations used to control modelGeometrically non-linear solution

Automatic component load transfer to CSA

Tool for FEA of componentsMultiple FEA solvers available to Virtual.Lab

Tool for DOE, Optimization, Reliability and Robust DesignUsed to calculate geometric sizing to achieve target stress


LMS Virtual.Lab LMS Virtual.Lab OptimizationOptimization



Stress Analysis – Boundary Conditions & Load Transfer

Demonstrates how Virtual.Lab Motion models can be used to generate boundary conditions for FEABraking & Turning Analysis cases added to Drop Test model’s specification tree

Differences in topology controlled by Design Tables & Configurations

Virtual.Lab Motion Contact forces used to simulate gaps in Lug – Side & Drag brace connectionsOuter Cylinder was flexible, other bodies rigid

Side & Drag braces roughly the same sizeProblem thought of as being statically

determinateMajority of compliance assumed to be in

Contact forces between Lug – Side & Drag braces

Automatic load transfer in Motion transfers and sets up Static Analysis cases for CSA at any time step(s)




Stress Analysis – Virtual Lab CSA ( CATIA GPS)

User choice for which FEA solver to useVirtual.Lab is compatible and scalable with

a number of different solversSame model used for Flexible bodies can

be used for stress analysisCSA had some advantages for this choice of process

Virtual Lab embedded, designer friendly FEA toolAuto flex & Load transfer capability with

Virtual.Lab MotionBest fit for the goals we established for this processParabolic tetrahedron elements usedGlobal mesh size 2in, local mesh size .25in


Stress Analysis – Virtual.Lab Optimization

Virtual.Lab Optimization obvious choice for calculating geometric sizing to achieve target stresses

One integrated approach to “optimization”for all Virtual.LabFull accessibility to Virtual.Lab

parameterization (Knowledgeware)Applicable to any Workflow captured in

Virtual.Lab.1 pad and 2 fillets added to part

Engineering judgment & basic solid modeling skill required

Dimensions of these features input to OptimizationMax Principal stress for both load cases calculated by CSAObjective – Determine sizing to achieve Max Stress < 120ksi


Stress Analysis Results

Starting Point:Outer Fillet Radius = 0.5inMax Principal Stress = 238.9 ksi

Optimization Result:Outer Fillet Radius ~ 2.25inMax Principal Stress = 114.7 ksi


Process Flow – Stress Analysis & Torque Link Optimization

Advanced Geometric Wireframe, Surface & Sold Geometric modelerParameterized Length of Torque Link

Tool for FEA of components & assembliesMultiple FEA solvers available to Virtual.Lab

Tool for DOE, Optimization, Reliability and Robust DesignUsed to calculate geometric sizing to achieve targets

LMS Virtual.Lab LMS Virtual.Lab OptimizationOptimization

LMS Virtual.Lab StructuresLMS Virtual.Lab Structures

LMS Virtual.Lab GeometryLMS Virtual.Lab Geometry

FEA SolverFEA SolverAny Solver that supports Analysis Objectives


Setting Up Optimization

Torque Link geometry modified so that length was driving parameterCAD Assembly was meshed using Virtual.Lab StructuresGap Connectors used to simulate complex load pathsVirtual.Lab compatible with a number of different FEA SolversVirtual.Lab Optimization used to determine optimum Torque Link Length

Torque Link Length was inputGoal was to minimize massMaximum Principal Stress was bound on Optimization

Torque Link Optimization

Braking Stress Before Optimization

Braking Stress After Optimization

Steering Stress Before Optimization Steering Stress After

Optimization

lms virtual.lab – the unified environment for … virtual.lab motion lms virtual.lab motion auto...

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