Realistic Simulation of a Flexible Mechanism using ANSYS Solutions. Achuth Rao, Ph.D. Product Line Manager Product Management Group ANSYS Inc.

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1 Realistic Simulation of a Flexible Mechanism using ANSYS Solutions Achuth Rao, Ph.D. Product Line Manager Product Management Group ANSYS Inc.

2 Solution Brands and Products Structural Fluids Explicit ANSYS/Mechanical Electromagnetics CFX/FLUENT ANSYS/Multiphysics Meshing ANSYS/AUTODYN Optimization ANSYS/EMAG ICEM CFD ANSYS/DesignXplorer

3 Geometry and CAD integration Benefits Support for all major CAD systems and file formats Bi Directional Associativity Parameter data types supported: Geometry CAD Parameters Material Properties Attributes (Loads; Constraints etc.)

4 Workflow: Dynamic Drop Test Analysis Benefits Integrated dynamics solver capability Reduces total solution time through meshing; pre processing; solution and post processing Accurate physical representation as compared to rigid multi body solvers Flexibility can be introduced when needed either based on component mode synthesis or full nonlinear analysis CAD associativity allows for easy parametric updated to design CAD: CATIA R17 ANSYS Workbench ANSYS DesignModeler ANSYS Simulation

5 ANSYS Flexible Multi body Dynamics Benefits Automatic connections setup Implicit structural solution Multi step transient analysis FE based rigid body analysis Nonlinear contact with friction Geometry based loading and processing of dynamics data Rigid to flexible part conversion Component Mode Synthesis (CMS) techniques for model reduction and flexibility

6 Connectors and FE Representation = Geometry representation FE Mesh Representation Connectors and contact behavior defined on geometry Equivalent FE representation though mass and connectors

7 Nonlinear Contact Modeling with Friction Contact Mesh Rigid rigid contact model between tire and runway Nonlinear frictional contact with between tires and runway Tire Representation: Tire stiffness and damping modeling using springs and dampers below runway Tire Stiffness and Damping K = lb/in C = 5 lbf-sec/in

8 Stiffness and Damping Characteristics Nonlinear Stiffness Curve 1800 Nonlinear Damping Curve

9 Landing Gear without Rotation and Contact Rotation of tires and contact with payment ignored Tire model approximated with a spring damper system Reaction vs Strut Stroke

10 Landing Gear with Rotation and Friction Rotation of wheel at approach speed of 150 mph Friction behavior with contact Tire model approximated with a spring damper system Reaction vs Strut Stroke

11 Dynamic Drop Test Analysis Reaction vs Strut Stroke

12 FMBD Solution Strategies & Benefits Traditional Techniques MESH PRE FEA CB MBD POST MESH PRE FE Based Approach FEA POST CB = Craig Bamptom Technique Savings FE based FMBD offers time savings in total solution time as compared to traditional approaches Made possible by an integrated solution environment combined with improvements in solver technology and high performance computing

13 Workflow: Static Analysis Benefits Easy model reduction and simplification for static analysis CAD associativity allows for easy parametric updated to design Advanced unified meshing tools from ANSYS, ICEM CFD, CFX and FLUENT Integrated design optimization & topological optimization solutions CAD: CATIA R17 ANSYS Workbench ANSYS DesignModeler ANSYS Simulation ANSYS DesignXplorer

14 Static Analysis: Cylinder & Lug Design Automatic connections and contact definition Geometry and FE based preprocessing and post processing Nonlinear geometry and contact capability Ability to run design changes through parametric model updates

15 Automatic contact and connections Connections and Contact Definition

16 Meshing and Pre processing Mesh Metrics

17 Static Analysis: Dynamic Braking & Turning Turning Loads Displacement Results Equivalent Stress Results

18 Parameter Manager & Design Optimization Parameter Manager across all applications: Design of experiments Design for six sigma and robust design Input and output parameters from CAD; material properties; boundary conditions and results and derived results variables

19 Geometry Updates and Design Parameters CATIA model update within ANSYS DesignModeler through parametric design Model updates can be transferred back to CAD system through bidirectional associativity

20 Automatic Mesh Updates with Design Parameters

21 Post processing through design iterations Reduced stresses levels Equivalent Stress Displacement Results Equivalent Stress Results

22 Topological Optimization Upper and Lower Torsion Links Minimization of Structural Compliance

23 ANSYS System Simulation Capabilities ANSYS Workbench provides an integrated solution environment for CAD geometry, meshing, CFD, implicit/explicit structural dynamics and optimization Landing Gear Acoustics Simulation using FLUENT Capabilities for system simulation of aircraft landing gear Structural dynamics simulation of landing gear Thermal analysis of landing gear brake assembly Brake squeal analysis of landing gear brake dynamics CFD analysis for landing gear noise simulation