A novel application of recovered stresses in stress intensity factors extraction methods for the generalized/extended finite element method

Summary An efficient improvement to compute Stress Intensity Factors (SIFs) in two‐dimensional fracture mechanics problems solved by Generalized/eXtended Finite Element Method and Stable Generalized Finite Element Method is proposed. A stress field obtained by a recovery procedure based on a locally weighted L2$$ {L}_2 $$ projection of the approximate stresses, is used in the formulation of two energy‐based SIFs extraction methods: the Contour Integral Method (CIM) and the Interaction Integral strategy. The accuracy and the path independence feature of the proposed approach are investigated in three numerical examples, considering crack opening modes I and II, different crack orientations and the presence of holes. The results demonstrate that the recovered stresses significantly improve the accuracy of the CIM and ensure a notable decrease in SIFs variation for different integration paths. On the other hand, an equivalent impact is not observed for the Interaction Integral strategy.