Controlling behaviour of constitutive models for rocks using energy dissipations

Abstract

The behaviour of rocks and other similar geomaterials is governed by different underling dissipative mechanisms that can be represented by damage and plastic strains in continuum constitutive modelling. The explicit links between these dissipative mechanisms and constitutive behaviour are established in this study in a generic thermodynamics-based framework. The key feature of this proposed framework and derived damage-plasticity models is the capability to control the constitutive behaviour through varying the contributions of different dissipative mechanisms to the total dissipation budget. Particularly, three fractions of the total dissipation budget related to damage, plastic volumetric and shear dissipations are introduced to control the constitutive behaviour through the evolution of damage variable and plastic strains, respectively. The examples provided show the performance and promising features of the proposed framework.