A novel micropolar peridynamic model for rock masses with arbitrary joints

A novel micropolar peridynamic model is proposed to simulate fracture behaviors of rock masses with arbitrary joints. The rock masses are discretized into a group of material points linked through two kinds of bonds, i.e. ordinary and joint bonds, which represent the mechanical behaviors of rock block and joint, respectively. The peridynamic parameters of ordinary and joint bonds are introduced to keep the consistence of the strain energy obtained from the proposed peridynamic model and from the continuum mechanics. The stress condition of the bond in micropolar peridynamic model is defined in terms of the displacement gradients of material points. Then a new stress-based failure criterion is proposed to describe the dynamic fracture for jointed rocks. The proposed model is verified by comparing its predictions with those from experimental observations. Numerical examples demonstrate that the wave transmission and crack development process of rock masses with different joint sets are well captured by the proposed model. Moreover, the influence of the joint geometry on failure characteristics of jointed rocks with an opening is further investigated by the proposed model.