*** ERROR # 312 ***

JasmineB
JasmineB Altair Community Member
in Community Q&A

I keep getting the following error message:

*** ERROR # 312 ***
In static load case 1
the compliance is negative or large 1.46469e+10.
Optimization/buckling analysis cannot be performed
due to possible rigid body mode.

What does this mean and how can I fix it? I have checked that my constraint DOF are the same as my loads and am unsure why the optimization is not running. I have attached the .hm and output file.

FinalUprightV2.hm
FinalUprightV2_004.out
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Best Answer

  • Adriano_Koga
    Adriano_Koga
    Altair Employee
    Answer ✓

    if you perform a simples analysis run (no optimization), it shows large displacements, meaning there are rigid body motions in your model, due to lack of constraint.

    image.png

    if you examine tyour model, you can find a couple non-connected nodes/elements. These are crucial for your model to run properly, and later, run optimization.

    You might want to equivalence these nodes or create a tied/freeze contact to glue them.

    image.png

Answers

  • Adriano_Koga
    Adriano_Koga
    Altair Employee
    Answer ✓

    if you perform a simples analysis run (no optimization), it shows large displacements, meaning there are rigid body motions in your model, due to lack of constraint.

    image.png

    if you examine tyour model, you can find a couple non-connected nodes/elements. These are crucial for your model to run properly, and later, run optimization.

    You might want to equivalence these nodes or create a tied/freeze contact to glue them.

    image.png

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