Shell & Solid Composite Modelling Different Behaviour

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

Dear Everyone,

 

I am have been working with the shell modelling of composites, using the PCOMP-card and plies and laminate definition. I wanted to take it to the next step and try the modelling of composites using 3D elements. I have looked into the Shell to Solid Conversion of HyperMesh first and then started on my own using the PCOMPLS card. I modelled the exact same plate twice to see if I can re-do my 2D results in 3D. However I came to find that both results are vastly different.

 

Do you know how this could happen? Displacement of 111 vs. 37...

I have attached both of my files, could any one of you please have a quick check?

 

Any help would be greatly appreciated!

 

Best Regards,

Lennart

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Answers

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

    Please find below some suggestion from my colleagues:

    1.Make sure you convert MAT8 to MAT9 (or MAT9ORT) correctly.  I always get messed up with v31 (OptiStruct MAT9ORT input) which is NOT equal to v13 (Typical value users have).  I’ve done a few studies between PCOMP/G, PCOMPLS, and PSOLID and I get “reasonable” match….but admittedly I have not done a conclusive test.  Also, double check your BCs…you have a few more nodes in PCOMPLS vs PCOMP/G that you have to get right between the two models. Just giving some guesses from my experiences.

     

    2.The solid shell has a thickness direction that needs to be defined properly. Take hex8 for example, grids 1 2 3 4 lie on bottom of the shell and 5 6 7 8 lies on the top of the shell.

  • Turbokraken
    Turbokraken Altair Community Member
    edited February 2019

    Dear Rahul,

     

    thank you very much for your answer.

    I still could not resolve the issue, even with reviewed material constants. Could you elaborate on what you mean with my BCs? (I assume you mean SPC?) I do have free nodes there but those where just for designing the part.

     

    BR,

    Lennart

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

    Yes I mean SPC constraints.Developement team suggested me to test shared file in internal beta build of 2019 version which yield closer with 2d & 3d element.

    There are some changes after 2018 which affect the results.