Three dimensional crack propagation through mesh-based explicit representation for arbitrarily shaped cracks using the extended finite element method

In this study a three-dimensional extended finite element modeling work is developed for crack propagation analysis of arbitrarily shaped crack(s) under mixed mode loading conditions. An explicit method is proposed for crack geometry characterizations, slicing of the enriched elements, and crack propagations. The method can be used to model multiple cracks propagation and allows for crack geometry transition from internal to surface, and further to through-thickness modalities under arbitrary loading conditions. Benchmark cases are studied and satisfactory agreement between theoretical and numerical results is observed. In addition, comparison between fully explicit and conventional implicit methods is made at different finite element mesh densities. The results show that compared to the conventional implicit method, there is a significant improvement in the obtained stress intensity factors for the fully explicit method at coarse linear hexahedral and quadratic tetrahedral meshes.