Your SlideShare is downloading. ×
Dummy Positioning by Pre-Simulation
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×

Saving this for later?

Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime - even offline.

Text the download link to your phone

Standard text messaging rates apply

Dummy Positioning by Pre-Simulation

867
views

Published on

Published in: Technology

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
867
On Slideshare
0
From Embeds
0
Number of Embeds
4
Actions
Shares
0
Downloads
32
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Innovation Intelligence®Dummy Positioning by Pre-SimulationFabien Breda / Lionel MorançayApril 2013
  • 2. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.• Franck Le Gall• Olivier Chertier• Franck Njilie• Upali Fonseka• Erwan MestresSpecial Thanks
  • 3. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.State of artCurrent dummy positioner are very efficient for small rotationFor big rotation, we may have intersections inside the dummyWhen it happens, users don’t know what to do and may think to the worst!!!
  • 4. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.Possible solutionsNothing• Simulation may crash…Remove manually intersections inside the self-contact of the dummy• Long• User-dependent• Change the characteristics of the dummyMake a pre-simulation• Long (isolate a model, construct the subsytem, set the boundaryconditions, update the model…)• Explicit solution is not so adapted for quasi-static solicitation• Importing results of another code is too long
  • 5. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.Focus on the pre-simulation solutionHypercrashRadiossMake a pre-simulation• Long (isolate a model, construct the subsytem, set the boundaryconditions, update the model…)• Explicit solution is not so adapted for quasi-static solicitation• Importing results of another code is too long
  • 6. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.HyperCrash: Sub-system extractionJoint N which leadsto intersectionsJoint N-1Joint N+1• Select the minimum part to be taken into account• Sub-system between Joint N+1, N-1• All the bones• Two new rigid bodies
  • 7. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.HyperCrash: Sub-system characteristics• Imposed displacement (quasi-static) : 0,314 rad in 500 ms around the axis of the joint (constant velocity for eachpositioning : 0,628 rad/s or 35°/s)• Two boundary conditions : one fixed the first rigid body, the second fixed except around the axis ofrotation/translation• Second rigid body with ICOG = 3 and COG at the center of rotation of the joint• Contact of the dummies
  • 8. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.Radioss Solution• Introducing Advanced Mass Scaling• Possible Applications• Roof crush• Stamping process simulation
  • 9. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.• Classical methods for raising time step• Increase of mass & momentum• All frequencies are affected• Non diagonal mass matrix• Assembling elementary matrices• de large enough to obtain the target time step• Added mass = zero / No change in total mass & momentum• Low frequencies are almost not affectedIntroducing Advanced Mass Scaling311113111131111312ed MM *
  • 10. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.Crash, Buckling, High Non Linear Contact, …Quasi Static , Non LinearDtx10 Dtx20Speed up• Decreases the number of cycles• Cost of a cycle is more than doubled• Solve using iterative method• Cost of solving depends on Matrix conditioningFM *Introducing Advanced Mass Scaling
  • 11. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.Roof Crush• TAURUS model 850K elements• Time step of 0.5ms raised to 10ms16 coresStandard 402044 cycles 33,4 hoursAMS 20146 cycles 4,2 hours x 7Standard AMSImpactor speed = 1m/s / total displacement = 200mm.
  • 12. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.• Number of shell elements : 331246• Dt ~ 0.2 ms (Element size < 2 mm) => more than 500 000 cyclesStamping Process SimulationNo AMSAMS x30
  • 13. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.• Elapsed times / Number of cycles• 48 CPUs, 48 SPMD domainsIntel(R) Xeon(R) CPU E5649 @ 2.53GHz (x86_64), 2533 MHz, 64449 MB RAM, 62403 MB swapElapsedtimeNumber ofcyclesSpeed up Time stepNo AMS 24177 sec 601260 -- 0,1979 µsAMS x 30 4939 sec 17839 4,9 5,937µsStamping Process Simulation
  • 14. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.Advanced Mass Scaling• Well adapted to Quasi-static applications• Energy content in high frequency domain is small• Stamping, Roof crush, …• May substitute to linear implicit solution if highly non linear• Easy to setup• No convergence issues• Research is still ongoing to make it usable in Frontal Car Crash• Performances factors 2 to 3 are usually obtained• Dtx10  5 ms for a 1M element model• w/ good energy balance• Quality of the results to be improved• To be coupled with RAD2RAD (MultiDomain)
  • 15. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.Radioss: Sub-system performanceOriginal Model Original ModelUsed of AMSDensity x1000Use of AMSTime step(natural time step :0,00036 ms)0,01 ms (~X 30) New natural time step: ~0,01 msAMS : 0,2 ms (X20)Performance onlaptop (4 cores 2,3Ghz with 16 GBRAM).Run with Radioss SP.Estimation ~10000secondes (2h40)1700 secondes 30-45 secondes
  • 16. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.Demonstration
  • 17. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.Enhancements : planning and possibilities• All parameters are under user control (available)• Possibility to run the simulation on servers (target 12.110)• Take into account initial constraint• Based on deformed geometry (X-REF) (target Hypercrash 12.110)• By importing initial stress in shells and solids (not yet scheduled)• Propose a re-mesh after the pre-simulation (not yet scheduled)• Propose a re-mesh and a mapping for initial states (not yet scheduled)• Plug this tool for Ls-Dyna profile (target Hypercrash 12.110)• Develop the same approach for seat deformer (target hypercrash 12.110)• One set of parameter by dummy (not yet scheduled)• Improve the interactivity• Warning message when simulation crashes• …• Coupling with other Radioss enhancements (Rad2Rad…)• …following YOUR FEEBACKS