Three-dimensional nonlinear strength criterion for rock-like materials based on the micromechanical method

In this paper, it is assumed the rock-like materials contain penny-shaped microcracks. The modes II and III stress intensity factors at tips of the three-dimensional penny-shaped microcracks are determined. The micro-failure orientation angle α is given out to describe the failure of rock-like materials. The formulation between the micro-failure orientation angle α and stress components is obtained from the mixed-mode fracture criterion. Failure...