Crack propagation in rock specimen under compressive loading using extended finite element method

Abstract

Understanding of mechanisms of initiation and propagation of rock fracture is a key factor in many engineering problems in rock. Since most failures in rock occur under compression condition, in this study, the crack propagation in rock specimen with inclined crack under uniaxial compression has been investigated. In order to simulate the crack propagation under compressive loading, the maximum tangential stress (MTS) criterion was firstly improved and incorporated in developed extended finite element method (XFEM) code. The XFEM allows crack growing through the finite element mesh without re-meshing process. The developed code is validated in different bench mark tests under tension by MTS criterion which can precisely predict the direction of crack propagation under tension condition. Different specimens with variation of inclined cracks under uniaxial compression are examined using the developed code. The results of modeling show that the crack growth direction is deviated from the initial crack direction and propagated from the crack tip toward the loading plates. The results obtained by the XFEM are in good agreement with the experimental and numerical results in the literature. It shows that the developed improved stress-based criterion in this study could be effectively used in modeling crack initiation and propagation under both tension and compression conditions.