nonlinear static structural analysis. Apply increasing load in steps & release.

David_R
David_R Altair Community Member
edited February 19 in Community Q&A

Using Optistruct & Hypermesh non linear static analysis, I wish to apply increasing load in steps and then release the load. I wish to see the residual deformation due to yielding of the structural steel once the applied load has been removed. 

This is not a transient time dependent scenario. I believe DLOAD, TLOAD1, TABLED1 cards may be relevant. 

1 - How are Optistruct users best able to learn this loading method? 

2 - where in the support documentation is this covered? This is a fundamental FEA topic.

Answers

  • Adriano_Koga
    Adriano_Koga
    Altair Employee

    you can perform NL Static Simulation in OptiStruct, for this.

    There are 2 ways:

    • multiple NL Static loadcases with each loadcase final load value as desired (using CNTNLSUB option to create subsequent loadcases)
    • single NL Static loadcase, using TLOAD1 and TABLED1 to create a pseudo-time table, with the carying load, as you've supplied in the table above.

    For option #1, I would just run 1st loadcase from zero to point 5, and then 2nd loadcase from 5 to 7, and last subcase removing all load.

  • David_R
    David_R Altair Community Member
    edited February 19

    Thanks.

    It was the CNTNLSUB option that I was not aware of & needed to add to my assumed method. This method then has the advantage that it allows different NLPARM, NLOUT, NLAPADT cards for each case.

  • Adriano_Koga
    Adriano_Koga
    Altair Employee

    correct. For multiple loadcases, you're allowed to use different setup. You could also try the newer NLCTRL which replaces most of these into a single card. There was an error displaying this embed.

  • Adriano_Koga
    Adriano_Koga
    Altair Employee

    i've found these around here… 1 example using 2 loadcases, and another with a single subcase, "time" dependent.