Using discrete rigid elements in thermal analysis?

[nonlinearRus]

Hi all,

I'm running a coupled temp-displacement model and I'm trying
to debug the model at the moment. The model consists of a
hyperelastic and viscoelastic material (foam) being
compressed by a (simple) indenter. I had been using
steel as the material for the indenter and it gave
accurate thermal conductivity results. However, the
creep I was expecting never transpired - I think it
was something to do with the steel-foam contact conditions.

I am now trying to use discrete rigid elements instead of
steel material elements for the indenter. The steel
elements were C3D8RT coupled temp-disp elements and
the rigid elements are R3D4 type, which are not thermally
active. The discrete rigid elements work well for creep
but now there is no heat transfer.

I am defining pressure dependent gap-conductance at
the contact interface, which has worked in the previous
model.

I would like to know can I use discrete rigid elements
in a thermal model? If so, how do I set up elements
so they can transfer heat?

Any help at all is appreciated!

NLR