Constitutive Theory Of Crystal Plasticity Under Non-Proportional Cyclic Loading

In this dissertation, a hardening law of crystal is proposed, which is suitable to describe the non—proportional cyclic hardening of polycrystalline. This hardening law is in conformity with the physical mechanism of work hardening and the crystal experiments, and meets the needs of uniqueness of crystal plasticity. Its validity is well confirmed by comparing the numerical calculations of polycrystalline with the experimental investigations under non—proportional cyclic loading.An iteration formulation for KBW theory under non—proportional loading and a method for determination of the active set of slips are also established, which are shown to be reliable and very efficient, when applied to the numerical calculations of polycrystalline under non-proportional cyclic loading.