Crack-mechanics damage and plasticity for rock-like materials under compressive loading

A crack-mechanics based model of rock together with plasticity under compressive loading is presented in this work.The propagation of wing crack in the micro-crack tip is characterized for rock damage,and the wing crack length is obtained based on the strain energy density for mixed-mode fracture.The distribution of micro-cracks is presented by the absolute volume strain with the two-parameter Weibull statistical model.The damage evolution variable of rock is employed by the distribution of microcracks and stress release volume.Voyiadjis’s strain hardening function is employed as the plastic yield function and plastic potential function.The elastoplastic damage model with its numerical algorithm is proposed and the code of elastoplastic damage model is implemented by using return mapping method.The plastic properties of the rock are analyzed from the respects of short micro-crack lengths,confining pressures.