3-DIMENSIONAL CONSTITUTIVE-EQUATIONS FOR RIGID PERFECTLY PLASTIC GRANULAR-MATERIALS

A three-dimensional constitutive equation governing the flow of an isotropic rigid/perfectly plastic granular material is presented. The equation relates the strain-rate tensor to the Cauchy stress tensor and to the co-rotational rate of the Cauchy stress. It contains scalar functions of the scalar invariants involving the stress, stress-rate and strain-rate tensors together with parameters which characterize the material. The model generalizes the double-shearing model and its relationship to existing theories is demonstrated. © 1990, Cambridge Philosophical Society. All rights reserved.