Answer:
For solids, no internal forces are available in the program. Converting stresses into internal forces would also be very complex, because not only would mx, my, mx be available, but also the torsional components mxy, myz, and mxz, as well as shear and axial forces. Normally, you only use a direct stress evaluation for solids.
If you still need internal forces, you have the possibility to refer the internal forces of a solid to a member. The result beam has been implemented in the program for this purpose.
