bending of composite tube

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

Hi dears,

 

I simulated the bending of a tube using MAT LAW 58. I am willing to capture fiber orientation after bending in Hyperwork. In other words, I want to know the change of shear angle after bending.

 

could you please help me how I can do that?

 

Any help would be appreciated,

 

Thanks so much,

Cna

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Answers

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited April 2019

    Hi Cna,

     

     

     material law 58 describes a hyperelastic anisotropic fabric material with no bending stiffness (used for composite forming simulation).  

     

     

    from  Reference Guide>Starter Input>Materials>Composite and Fabric Materials>/MAT/LAW58 (FABR_A)

     

    This material uses the anisotropic coordinate system, with the angle between the material coordinate system axes (anisotropy angle) updated based on the element deformation. Special user-defined output should be used to evaluate stresses, strains, and the shear angle alpha. In the /TH/SHEL and /TH/SH3N entries in the Starter file and in /ANIM/SHELL in the Engine file, you should specify the following:

    • USR1 - stress in fiber direction 1
    • USR2 - stress in fiber direction 2
    • USR3 - stress in shear direction
    • USR4 - strain in fiber direction 1
    • USR5 - strain in fiber direction 2
    • USR6 - tan(α)

     

    2
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  • Cnaaaaa
    Cnaaaaa Altair Community Member
    edited April 2019

    Thanks so much for the useful information.

     

    My purpose is composite thermoforming too and this material model appropriately modelled wrinkling as shown in the attached file.

     

    Could you please let me know how I should specify user-defined outputs? should I write python code for it (like in ABAQUS) or it is available in default? 

     

    I checked the user manual for  /TH/SHEL and it seems that USER1,2..,6 are available just for material model 29, 30, 31, and 52! 

     

    I appreciate any kind of help,

     

    Cna

     

     

    <?xml version="1.0" encoding="UTF-8"?>fine mesh_wrinckling.png

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited April 2019

    No code writing is required, simply set up appropriate output requests:

    -for Hyperview output use ANIM/SHELL where USRi set NUM_cards to 6 and input numbers 1 through 6 in the Data:i table

    -for Hypergraph output use  /TH/SHEL and/or /TH/SH3N where NUM_VARIABLES is set to 6 and input USR1 through USR6 in Data:Var table 

     

    A simple model with such output requests is attached.

    Unable to find an attachment - read this blog

  • Cnaaaaa
    Cnaaaaa Altair Community Member
    edited April 2019

    Thanks so much Ivan.

    I really appreciate your help. It was very useful.

     

     

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