Dear Lars,

the only simple way (no coding) is to simply use more elements. But this is probably not what you want.
The are some other options, but require some coding:
- as the displacement interpolation is fully determined from nodal values, you can easily post-process element data by writing some specialized code. The same applies for internal forces and moments.
- one can do the same internally in oofem, by writing specialized export module, for example.

Borek