Thank you very much, this helps a lot. With that, I was able to create input files for some simple simulations for 2D solids. The results seem to be reasonable.
I have a follow-up question:
Does the "PERIodic HILL" command work within the complex arithmetic?
I used it assuming that it would produce a real-valued strain which seems to work. However, even though I have included viscoelastic behavior, the imaginary stress is zero. I would have expected it to be nonzero.
Kind regards