A NEW FORMULATION OF CONSTITUTIVE MODEL FOR HYPERELASTIC-CYCLIC PLASTICITY

Until now, a number of classical hyperelastic-finite plasticity constitutive models have been proposed. However, most of them are based on the classical Armstrong-Frederick kinematic hardening rule in consideration of the complexity brought by the introduction of the intermediate configuration in the hyperelasticity theory. Hence, based on the existed constitutive theories, the methodology of Lion decomposition theory was extended utilizing the notion of the multi-mechanism process and clearly put forward the conception of the multi-intermediate configuration. Furthermore, the classical concept of the objectivity in the continuum mechanics for better application to the hyperelasticity theory was generalized and then a new hyperelastic-finite plastic constitutive model was proposed. The new constitutive model not only meets the thermal dynamic laws but also can incorporate several classical kinematic hardening rules which were usually adopted in cyclic plasticity of infinitesimal deformation theory (e.g. the A-F model, Chaboche model, O-W model and the K-O model, etc.). Therefore, this model corresponding to finite deformation problems contains two typical characteristics adopted by infinitesimal deformation theory: the additive decomposition property and step mutation feature of the backstress on the critical surface. Thus, the present model can be treated as parallel to the corresponding form in the small deformation case. Finally, the situation accounting for Karim-Ohno kinematic hardening rule is under specific consideration and compared with the hypoelasticity constitutive model.