LMS Virtual.Lab The Unified Environment for Functional Performance Engineering LMS Imagine.Lab LMS OPTIMUS LMS Engineering and Deployment Services Technology Transfer Process Transformation & Best Practices System Support LMS SCADAS Mobile - Lab LMS Test.Lab LMS Tec.Manager LMS Virtual.Lab Motion, NVH, Acostics, Optimization 1 copyright LMS International - 2007
Strategy and Assumptions CAD Data could have come from UGS, Pro-E, Solidworks, Autodesk, Parasolids Interface with all FEA Tools, ABAQUS, NASTRAN, ANSYS, UGS - NX, PERMAS, or CATIA GPS Modeled using a Scalable Approach without having to switch between different products. Reasonably accurate results for early trade off studies vs. high accuracy for test correlation Provide 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 typical Preliminary Design Decision Process. 2 copyright LMS International - 2007
Process Flow Drop Test Tool for modeling and simulation of multi-disciplinary systems (hydraulic, pneumatic, thermal, mechanical, controls, etc.) Design of Oleo System 1-D Representation of Landing Gear Reuse AMESim Oleo System Model LMS Virtual.Lab Motion LMS Virtual.Lab Motion Auto Flex Tool for 3-D Multi Body system design Validate Oleo system with 3-D Landing Gear Model and Flexible Modeling for Critical Components 3 copyright LMS International - 2007 Tool for FEA of Components Provides Craig-Bampton modes for Flexible Bodies
Drop Test Model Oleo Dynamics Starting Point : 1D AMESim Model of Landing Gear Initial 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 4 copyright LMS International - 2007
Drop Test Model Tire & Lift Forces Tire Forces Calculates & Applies forces at the tire contact patch between ground and wheel body in up to 3 directions when in contact Choice 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) z w eff β eff belt r eff eff. road plane F z SWIFT model structure Ω wheel rim V F x ϕ -ψ. C residual springs actual road surface γ ϕ* wheel plane belt _ V c α _ V * α* M z F y Based on data provided & goals of the process, Simple Tire force was used Lift Force 3 Point force applied to aircraft in global z direction equal to total weight of aircraft + gear Aircraft weight is parameter to this force pac 2004 5 copyright LMS International - 2007
Drop Test Model Contact Forces Large gaps present in Lug Drag & Side Braces Virtual.Lab motion Contact forces used to simulate these gaps Based on Hertzian formulation, very stable, fast & accurate Added to drop test model but required for Stress analysis portion 6 copyright LMS International - 2007
Drop Test Model - Flexibility FEA required to calculate mode shapes as input Tough choice about which FEA solver to use Virtual.Lab Motion is compatible with a number of different solvers Can reuse models between Drop Test & Stress Analysis with any of these solvers Craig-Bampton mode set drivers available CATIA GPS chosen because of Auto Flex capability Easiest setup of Flexible Bodies Fully Associative with geometry Select Rigid Body in mechanism model the Mesh & FE load cases are automatically defined 2 nd Craig-Bamption mode 106Hz 7 copyright LMS International - 2007
Drop Test Results 8 copyright LMS International - 2007
Drop Test Load Stroke curves Load - pounds Stroke - inches 9 copyright LMS International - 2007
Process Flow Stress Analysis LMS Virtual.Lab Motion Reuse Flexible Drop Test model to generate BC for stress analysis Design Tables & Configurations used to control model Geometrically non-linear solution LMS Virtual.Lab Optimization Tool for DOE, Optimization, Reliability and Robust Design Used to calculate geometric sizing to achieve target stress Automatic component load transfer to CSA LMS Virtual.Lab Motion Auto Flex Tool for FEA of components Multiple FEA solvers available to Virtual.Lab 10 copyright LMS International - 2007
Stress Analysis Boundary Conditions & Load Transfer Demonstrates how Virtual.Lab Motion models can be used to generate boundary conditions for FEA Braking & 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 connections Outer Cylinder was flexible, other bodies rigid Side & Drag braces roughly the same size Problem thought of as being statically determinate Majority 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) LMS Virtual.Lab Motion Auto Flex LMS Virtual.Lab Motion 11 copyright LMS International - 2007
Stress Analysis Virtual Lab CSA ( CATIA GPS) User choice for which FEA solver to use Virtual.Lab is compatible and scalable with a number of different solvers Same model used for Flexible bodies can be used for stress analysis CSA had some advantages for this choice of process Virtual Lab embedded, designer friendly FEA tool Auto flex & Load transfer capability with Virtual.Lab Motion Best fit for the goals we established for this process Parabolic tetrahedron elements used Global mesh size 2in, local mesh size.25in 12 copyright LMS International - 2007
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.Lab Full 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 Optimization Max Principal stress for both load cases calculated by CSA Objective Determine sizing to achieve Max Stress < 120ksi 13 copyright LMS International - 2007
Stress Analysis Results Starting Point: Outer Fillet Radius = 0.5in Max Principal Stress = 238.9 ksi Optimization Result: Outer Fillet Radius ~ 2.25in Max Principal Stress = 114.7 ksi 14 copyright LMS International - 2007
Process Flow Stress Analysis & Torque Link Optimization LMS Virtual.Lab Geometry Advanced Geometric Wireframe, Surface & Sold Geometric modeler Parameterized Length of Torque Link LMS Virtual.Lab Structures Tool for FEA of components & assemblies Multiple FEA solvers available to Virtual.Lab LMS Virtual.Lab Optimization Tool for DOE, Optimization, Reliability and Robust Design Used to calculate geometric sizing to achieve targets FEA Solver FEA Solver Any Solver that supports Analysis Objectives 15 copyright LMS International - 2007
Torque Link Optimization Torque Link geometry modified so that length was driving parameter CAD Assembly was meshed using Virtual.Lab Structures Gap Connectors used to simulate complex load paths Virtual.Lab compatible with a number of different FEA Solvers Virtual.Lab Optimization used to determine optimum Torque Link Length Torque Link Length was input Goal was to minimize mass Maximum Principal Stress was bound on Optimization Braking Stress Before Steering Optimization Stress Before Optimization 16 copyright LMS International - 2007 Setting Up Optimization Braking Stress After Optimization Steering Stress After Optimization