New Kinematic Hardening Model

The present paper proposes two rules to develop a new kinematic hardening model. The first rule regulates the movement of the yield surface. It states that during loading, the yield center moves such that the kinematic hardening of the yield surface results in a plastic strain rate that an isotropic hardening model would also predict. The second rule introduces a new concept, the hardening center, and assumes that whenever the direction of the loading path undergoes abrupt change, the hardening center immediately shifts to the current center of the kinematic hardening yield surface. A tube problem is solved to demonstrate this new model. It is shown that this model is able to describe all the possible responses of the material, satisfy those aspects of material behavior that are generally deemed essential, and permit various forms of the plastic modulus to be used to correlate with experiments, while still being simple and mathematically tractable.