A flow rule based on Huddleston's multiaxial rupture criterion as a yield function

An elastic-plastic constitutive equation is proposed to develop a continuum damage model for multiple flawed medium. The constitutive model takes into account the effect of hydrostatic stress to describe the decrease of rigidity and flow stress in tension and has an extended form of Huddleston's equi-rupture function. The decrease of those properties due to an evolution of damage is described by a proper selection of parameters in the yield function in accordance with a state of damage. Some case studies are shown. The model can be extended to include the kinematic and combined hardening rules or incorporated in constitutive equations for finite element calculations such as unified models. (orig.)