XFEM with high-order material-dependent enrichment functions for stress intensity factors calculation of interface cracks using Irwin's crack closure integral

The performance of the proposed method is validated on several benchmark examples involving straight and curved interface cracks. In particular, we examine the effect of enrichment order, mesh refinement, bimaterial mismatch, crack tip position, and integration limit of Irwin's integral. The method is shown to work well on all examples, giving accurate SIF results. Furthermore, while the popular interaction integral method requires special auxiliary fields for curved interface cracks and also needs cracks to be sufficiently apart from each other in settings with multiple cracks, none of these limitations are required by the proposed approach.