Nonlinear quasi-static analysis optimization

Amasker
Amasker Altair Community Member
edited October 2020 in Community Q&A

Hi，

recently i am simulating the beam under three-point bending conditions.I want to apply displacement load on the beam，Thereby obtaining the maximum reaction force。

 

Taking the thickness of the beam as a design variable，mass as objective。load step is Nonlinear quasi-static analysis...There is a fatal error

 

image.png.ff08ddf19c1b689c1478d77a04b6cb69.png

 

 

How to solve this problem？Can Optistruct be optimized in nonlinear quasi-static analysis?

 

 

 

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Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited March 2019

    Error clearly says that optimization for large displacement is not supported. If you have PARAM LGDISP 1 defined in your model then give a try without this card.

  • Amasker
    Amasker Altair Community Member
    edited March 2019

    Thank you

     

    I don't figure out the what is PARAM LGDISP card，I have deleted the MATS1，and update the displacement load as 0.8mm。the problem is still there

     

    the following is .fem file，could you give some advice

     

     

    Unable to find an attachment - read this blog

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited March 2019

    I see  PARAM control card is available in your deck. Control card: PARAM: Deactivate LGDISP,1 

    <?xml version="1.0" encoding="UTF-8"?>PARAM.JPG

  • Amasker
    Amasker Altair Community Member
    edited March 2019

    Thank you @Rahul R

     

    It worked，I want to set contact force（reaction force） as dconstrains，but I don't know how to set response？

     

    Is there any related tutorial or example on the official website?

     

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited March 2019

    Contact pressure and contact force from both S2S and N2S contacts can now be used as a response (DRESP1) in optimization formulation.New optimization response is supported in OptiStruct version 2018.PFA same deck for same where we used contact force as constraints.

    Unable to find an attachment - read this blog

  • Amasker
    Amasker Altair Community Member
    edited March 2019

    Thank you @Rahul R

     

    After applying  the elastoplastic property, the analysis type is changed to nonlinear quasi-static analysis. Why is the calculation time so long, is my parameter setting wrong?

     

    This kind of nonlinear quasi-static due to materials generally needs to set which parameters to improve the calculation efficiency？

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