Numerical simulation on effect of heterogeneity on mode I fracture characteristics of rock

Abstract

Rock is more sensitive to tensile loading than compressive loading, since the tensile strength of rock is much lower than compressive strength. The fracture characteristics of rock in the tensile state are of great significance to the understanding of rock failure mechanisms. To this end, we have conducted numerical simulation researches on mode I cracking process of rock with varying homogeneity, using the Realistic Failure Process Analysis program. With the increase of homogeneity, cracks are concentrating to the ligament area with a decreasing number of crack bifurcations, and the main crack path is becoming smooth. Crack behaviors and mechanical properties are influenced significantly when the homogeneity index is in the range of 1.5 to 5. When the homogeneity index is greater than 30, they are not affected by rock homogeneity and the rock can be considered as essentially homogeneous. It is considered that the global and local strengths are affected by the distribution of rock mechanical properties at mesoscale, which influence the crack behaviors and mechanical characteristics.