This page shows the results for a tension-torsion test specimen made of a FCC single crystal material. The material is modeled with cubic elasticity, and viscoplastic deformation on its 12 octahedral and 6 cubic slip systems. Each slip system allows kinematic hardening (scalar with sign) and isotropic hardening (scalar).
The crystal is oriented off-axis, to provide unsymmetric loading on the individual slip planes within the systems. The specimen is subjected to a cyclic rotation about the specimen axis with zero axial displacement.
Each slip system is modeled using internal variables for
a yield zone length, R, and a kinematic offset, X.
The slight off-axis rotation of the crystal creates an
in-homogeneous distribution of slip. Interaction is seen
between the cubic system (left) and the octahedral system
(right). These plots are of the summed magnitude of plastic flow
for all slips of the octahedral and cubic systems.