What's the problem with this non-convergent solution?

PuddingBaer91
PuddingBaer91 Altair Community Member
edited June 2022 in Community Q&A

Hi there,

i try to simulate a hyperelastic structure with large displacement and contact conditions. Sadly the simulation is not converging. Sometimes the displacement steps are just showing an excepted behaviour but the simulations stops because convergence fails. Often the simulation stops and i can see a very strange and extreme displacement like an "element explosion".

Could you please help me.
What is the problem here?
How can i solve this problem?
How should i tune the contact settings for the attached structure?

Thank you very much for your help :)

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Answers

  • Robinson Ferrari_20451
    Robinson Ferrari_20451
    Altair Employee
    edited June 2022

    Hi,

    For your model, I'd suggest using DTRAN (nonlinear transient) analysis since is common to face some buckling for models like yours.
    Please try using penalty SOFT since you are facing element distortion (element explosion). It should help you here.
    Also try to split your contacts instead of only using self-contact specifically for the rubber (it's really hard to converge self-contact with hyperelastic materials).
    To use only UP tolerances can help you, and use NOPCL=0 in NLADAPT as well. Perhaps using a different value for SRCHDIS (for instance 2.0) can help you, too.
    I hope all this helps you. Please don't forget to let us know by marking the answer as correct and including some comments below.


    Thank you

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