How to output element stiffness matrix to ASCII file in Optistruct

Anoop_20407
Anoop_20407 Altair Community Member
edited October 21 in Community Q&A

Hello everyone,

I’m beginner in use Optistruct and currently working on solving a static linear elastic problem. I’ve been trying to find a way to output the element stiffness matrix to a ASCII result file. Could someone please guide me on whether this is possible and, if so, provide instructions on how to achieve this?

Your assistance would be greatly appreciated.

Thank you in advance!

Anoop 

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Best Answer

  • Robinson Ferrari_20451
    Robinson Ferrari_20451
    Altair Employee
    edited December 2023 Answer ✓

    Hi Anoop,

    Please try using the OUTPUT,MATRIX card (OUTPUT,MATRIX,REDUCED if reduced format is desired) to obtain the mass and stiffness matrices in ASCII format.

    Thank you very much,

    Robinson

Answers

  • Robinson Ferrari_20451
    Robinson Ferrari_20451
    Altair Employee
    edited December 2023 Answer ✓

    Hi Anoop,

    Please try using the OUTPUT,MATRIX card (OUTPUT,MATRIX,REDUCED if reduced format is desired) to obtain the mass and stiffness matrices in ASCII format.

    Thank you very much,

    Robinson

  • Robinson Ferrari_20451
    Robinson Ferrari_20451
    Altair Employee
    edited December 2023
    Robinson Ferrari_20451 said:

    Hi Anoop,

    Please try using the OUTPUT,MATRIX card (OUTPUT,MATRIX,REDUCED if reduced format is desired) to obtain the mass and stiffness matrices in ASCII format.

    Thank you very much,

    Robinson

    https://help.altair.com/hwsolvers/os/topics/solvers/os/output_io_r.htm?zoom_highlight=output+matrxi

  • Anoop_20407
    Anoop_20407 Altair Community Member
    edited December 2023

    Thank you @Robinson Ferrari, your suggestion worked.

  • Pedro_Millan
    Pedro_Millan Altair Community Member
    edited October 21
    Robinson Ferrari_20451 said:

    Hi Anoop,

    Please try using the OUTPUT,MATRIX card (OUTPUT,MATRIX,REDUCED if reduced format is desired) to obtain the mass and stiffness matrices in ASCII format.

    Thank you very much,

    Robinson

    Dear Robinson,

     

    I am using, successfully, the OUTPUT,MATRIX,FULL,SPARSE to output the stiffness and mass matrices, however, when it comes to the mass matrix, it omits the rotational inertia of the nodes that have 6DoF (corresponding to shell elements). Do you have any idea why this is happening and/or how to solve it? 


    Thank you very much.

     

    Best regards,

    Pedro Millan

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