Computation of mixed-mode stress intensity factors for curved cracks in anisotropic elastic solids

A numerical procedure, based on the concept of the J_k-integrals, is presented for computation of the mixed-mode stress intensity factors for curved cracks. Since no auxiliary solutions are required in practice, this approach can be applicable for problems containing cracks of arbitrary curved shape in generally anisotropic elastic solids. Nevertheless, while these integrals are demonstrated to be path-independent in a modified sense, it is noted that the near-tip region is always inevitably included. Attention is therefore addressed to modeling of the singular behavior in the vicinity of the crack tip in such manner that the calculation is based on a combination of full-field finite element analysis and near-tip asymptotic results. With this, no particular singular elements are required in the calculation.