Extended finite element method for fracture mechanics of rock

Key words:  extended finite element method  level set method  stress intensity factor  interaction integral method  crack propagation criteria  crack propagation path

Abstract:

An extended finite element method (XFEM) was used to study the mechanical characteristics and crack propagation behaviors of rock materials, in which the methods for selecting the element displacement mode, the geometric description of plane cracks and the integration of special elements were introduced. The criteria for crack propagation in terms of the maximum hoop stress and an interaction integration method for calculating the stress intensity factor were introduced to formulate the fundamentals of the XFEM model in fracture mechanics of rocks. Then the XFEM model was developed to predict the mechanical behaviors of fractures in rocks, and the model was solved numerically using the MATLAB software. The stress intensity factors of the crack type I and the crack propagation paths of the crack type II were calculated and analyzed using the XFEM model, respectively. The calculation results show that the proposed XFEM method is viable to effectively simulate the crack propagation process and to calculate the fracture mechanics parameters in rock materials.