Realistic Simulation of a Flexible Mechanism using MSC.Software's ...

Realistic Simulation of a Flexible Mechanism using MSC.Software’s SimEnterprise Solutions Baskar Rajagopalan Product Manager, MSC.Software

MSC SimEnterprise Solution Set Model development • • • • •

SimXpert Structures, Motion Workspaces Expert/method analyst focus Advanced MD environment Best practice author/capture for re-use Simulation process automation

MD Workspaces

MD Nastran / SimXpert Motion Solver Technology • • •

Common, Multi Discipline embedded solver foundation Cross platform all-in-one simulation engine Enterprise computing access via gateway

High Level Solution Process CATIA Data

Simulation Model

Results MD Nastran / SimXpert Motion • Drop test Simulation • Flexible Body Motion • Structures Optimization

Landing Gear Simulation Process •

Process Details – Attach to initial geometry in CAD models – Develop a multi-body dynamics (MBD) model of the LG assembly • Include flex bodies where appropriate • Inner & outer cylinder only

– Use MBD model to simulate rigid and flexible landing conditions – Extract time domain loading conditions from the flexible landing simulation – Develop an FE model of the LG assembly • Re-use flex parts & joints from MBD model

– Use FE model to simulate quasi-static applied loads – Apply the quasi-static applied loads and simulation loads to topological optimization of the LG assembly components – Update geometry of the LG components based on simulation(s)

Landing Simulation Results

AVI

Landing Simulation Results Load-Stroke Response

Vertical tire reaction

Damping coefficient •

Initial damping curve resulted in loads outside design envelope

•

SimEnterprise supports simulation of active damping and shock strut metering pin design – For this study the revised curve was obtained through simple iterative studies

CD

S

Damping Coefficient Vs Stroke

Landing & Taxiing Simulation Process •

Process Details – Utilize CATIA geometry – Model lugs so they can be easily modified without affecting the cylinder meshes – Mesh solids – Define properties – Define contacts at joints and “glue” lugs back on – Conduct static analysis based on loads from dynamic landing simulation and known braking/turning loads – Review results

Braking, Turning and Landing - Simulation Results

Braking

Turning

Landing loads

Design Optimization •

Process Details – Define ‘design’ region – for this demonstration the upper and lower links were considered ‘designable’ – Conduct topology optimization (MD Solver technology) to determine distribution of material in links – Review results and output geometry from topology optimization back to CAD system – Define new geometry in CAD system that allows the definition of design variables for shape optimization – Conduct shape optimization for design variables

Link Optimization Topology design regions

Optimized topology

Optimized topology to CAD Imported to CAD

Smoothed….

Optimized topology

Refined CATIA Geometry

Lug Design Evolution • •

Engineering judgment leads to addition of fillet radii Shape optimization quantifies optimal radii dimension

Summary / Closing Comments • •

Flexible landing gear simulation process successfully completed Leveraged key strengths of SimEnterprise solution set – Single simulation environment – Model re-use across disciplines – common data model – Integrated MD solver – Native access to CAD geometry – no translation

•

Additional capabilities not demonstrated – Control system integration - active damping – Fluid/gas simulation of shock strut with metering pin – Feature optimization based on mesh morphing – Integration of flight dynamics