Hello together
I would like to export the thermal matrices (heat capacity, thermal conductivity and load) of a transient heat transfer simulation for a research project. I need the matrices in mtx format so that I can continue working with them.
So far I have tried the following additional lines in the inp file:

*Element Operator Output, Assembled, Stiffness, Damping, Load

*Operator Output, Operator=Assembled, Solution, Load, Free Body Response, Stiffness

and

*Step, name=export_data
*MATRIX GENERATE, STIFFNESS, MASS, ELEMENT BY ELEMENT
*MATRIX OUTPUT, STIFFNESS,MASS, FORMAT=MATRIX INPUT
*End Step

None of the options allowed me to export the matrices in mtx format. The only thing I managed to do was to export them in sim format, but I can't continue with that.

Do you have any idea how else I could try or where my error lies?
Thank you very much