Two complementary trios material model and experimental simulations of SAE 4340 and RHA

A two-complementary-trio material model for cyclic plasticity is proposed in this paper. In this formu-lation we consider a contact surface to confine the motion of contact stress. While the on-off switching criteria of plasticity are derived from the first complementary trio, the switching criteria of kinematic hardening rules are derived according to the second complementary trio. In terms of the new concept of contact stress and contact surface, it becomes easier to derive the governing rule of back stress during the contact of yield surface and bounding surface. The validity of the new model is confirmed by comparing the computational results with the experimental data for materials of SAE 4340 and RHA under uniaxial cyclic tests and biaxial cyclic tests. Even though the material constants used in the new model are parsimonious (with only 12), it is immediately recognized that the cyclic response curves described by the new model are in good agreement with the experimental data. 1.