The yield surface for most plasticity models in APDL is implemented as the von Mises yield criterion. The other yield surface is the hill yield criterion. You cannot choose tresca or any other yield surface unless you delve into defining your own material models (of which I am not experienced in and cannot gaurantee is actually possible).n can also head to your install directory to check out examples of subroutines.nC:/Program Files/ANSYS Inc/v202/ansys/customize/usernIt seems as though other codes also operate like thisn