An energy-driven crushing-plasticity coupling model for grain crushing in porous rocks

This research develops an energy-driven constitutive model designed to tackle the complex phenomenon of grain crushing in porous rocks. Initially, a novel coupled relationship is proposed to integrate various energy dissipation mechanisms, including both plastic and crushing effects, using spherical polar coordinates. This approach results in a robust coupling of energy dissipation, providing a comprehensive depiction of the influence of grain crushing on plastic deformation. An energy-based yield criterion is then formulated by comparing elastic potential energy contours with experimental findings, and the behaviour of crushing hardening is examined through energy evolution. Flow rules are subsequently derived, both independently and with consideration of plasticity-crushing coupling. Finally, validation against a range of experimental tests highlights the model's versatility. The proposed model enhances the understanding of rock-crushing issues from an energy perspective and demonstrates simplicity with only 4 or 5 easily calibrated parameters.