OptiStruct Matrix Export

Question

Hi,

I'm looking for a way to export the stiffness matrix in OptiStruct.

Using OUTPUT,MATRIX,FULL,SPARSE works, but it generates the matrix in ASCII format, which is far too slow for my use case (large model).

Is there a way to export the stiffness matrix in a binary format instead?

AeroSpace · Answer

Hi,

yes, I tried param,post,-5. The file is created and the performance is good, but the output format is unclear and doesn't appear to be documented. That makes it somewhat difficult to use. It also doesn't seem to be in Nastran format.

After spending quite some time investigating it, it has reached a dead end.

Alberto Campagna · Answer

Hi,

you can try with PARAM, POST, -5. This should create a *.k.op2 file with the stiffness matrix.

Kind Regards

Alberto