A general weight function approach to compute mode-II stress intensity factors and crack paths for slightly curved or kinked cracks in finite bodies

A simple procedure is proposed that allows computing the stress intensity factors for slightly curved and kinked cracks in finite bodies. Basis of the method is the computation of the stress field around a straight crack under externally applied tractions. Then, this auxiliary crack is replaced by the crack of interest. The stress intensity factors are computed from the stresses caused by the auxiliary crack using the weight function technique. In a practical application of the method, mode-II stress intensity factors are computed for the edge-cracked half-space. From the usual crack path condition, KII = 0, the paths of propagating cracks under biaxial loading and the critical biaxiality ratio for global directional instability are computed. The results are in very good agreement with finite element computations.