Upper-bound rigid-plastic constitutive model for mixed-hardening materials with micro void evolution process

An upper-bound rigid plastic constitutive model for porous materials with mixed-hardening property is constructed in this paper. To overcome the obstacles to the establishment of rigid plastic theory, a few concepts with clear physical meanings are defined and a series of mathematical transformations are introduced in the model. Brief discussions are made to reveal the modelʹs characteristics and self-consistency. The close relationship between the present research and previous one is systematically explained. Simple calculation results are presented to show the reasonability and reliability of the model.