NLFE Bodies in Hypermesh?

Simon Križnik
Simon Križnik Altair Community Member
edited October 2020 in Community Q&A

Hi,

 

can  Non Linear Finite Elements (based on Absolute Nodal Coordinate Formulation or ANCF) be created with Hypermesh preprocessor?

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Answers

  • Felipe M Leila
    Felipe M Leila New Altair Community Member
    edited April 2020

    Hi Simon,

    No, it is not possible to use Hypermesh to create the NLFE geometry. There are 18 different cross-sections possible in MotionView though, and you can also combine them to form a generic shape.

     

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    Best regards,

    Felipe.

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited April 2020

    Thanks for your response.

     

    Hopefully, NLFE will be supported in a future version of HM.

     

    As a workaround, is it possible to append Motionsolve xml commands with BULK or CASE_UNSUPPORTED_CARDS?

  • Chris Coker_21312
    Chris Coker_21312 New Altair Community Member
    edited April 2020

    Hi Simon-

    To answer your next question, the answer is no.  The motionsolve .xml commands have no relationship with traditional FE solver 'Cards'.  We have several macros for creating systems that utilize the most common use cases for NLFE.  Those are located on the vertical toolbar just to the left of the main GUI screen.  With these, you can create NLFE springs, NLFE stabilizer bars, and Belt-Pulley systems.

     

    If you can give us more details about what you are trying to simulate, maybe we can suggest an appropriate approach.

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited April 2020

    Hi Chris, thanks for your interest.

     

    The objective is to design a compliant mechanism by performing integrated structural and system level optimization (similar to OS-E: 4015 Optimization of MBD System Level Response). Flexible links are modeled with CMS flexbodies and hinges (small length flexural pivot) with NLFE. HM is preferred because it is easier to modify flexbody mesh and use Hypermorph to generate shape design variables, as opposed to Motionview where parameterization is done with hardpoint coordinates and there is no way to modify the mesh once it is imported. 

  • Chris Coker_21312
    Chris Coker_21312 New Altair Community Member
    edited April 2020

    This question is probably better posed to the HM forum, since that's the tool you'd prefer to use.  Note the the MBD capabilities within HM/OS are not widely used, and I don't think have complete coverage of entities.

     

    Note, there are some methods, using Hyperstudy, and combining MotionView/MotionSolve and Optistruct to modify the flexbody per each run.  It requires some custom scripting, but we have some of our commercial customers using this approach.

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