Numerical simulation of crack growth through particulate clusters in brittle matrix using the XFEM technique

The purpose of the present work is a numerical study of the interaction between a crack and second phase particles in a reinforced composite material. Simulations are accomplished using the extended finite element method (XFEM) without tip-enriched functions, a new domain expression of an interaction integral for evaluating stress intensity factors, and the maximum hoop stress criterion for crack-growth direction prediction. Crack deflection mechanisms and the associated energy release rate variations are investigated. It is found that although the energy release rate is affected by the particle at relatively large distances, the crack trajectory is not substantially altered until the crack is very close to the particles. A pre-existing interface crack is also observed by introducing adaptive enriched functions in the XFEM. By this method, expensive meshing strategies can be avoided and considerable flexibility is obtained. The results show that the flaw could attract the main crack and increase the energy release rate.