Error 312

Altair Forum User

In a topology optimization I get the following message

ERROR # 312 FROM SUBROUTINE clcuku

In static load case 1 the compliance is negative or large -1.976274E+06

Optimization/buckling analysis cannot be performed due to possible rigid body mode

I've verified all elements/nodes are attached, it's a running nastran model. I have 4 components to be optimized. This is the first time I've run multiple design spaces in 1 analysis. Each design space is independant of each other but but attached to the surrounding structure.

Altair Forum User

Hello,

From all I know, the error 312 comes from the fact that the allowed constraint (displacement,...) or the loading are too important. It is strange that you can have results from Nastran (but you may only run an FE analysis, not an optimization).

Try to reduce the range of contraints allowed (since I suppose that your loading cannot be changed).

Let me know if you succed.

Regards.

Arnaud