Symmetric Galerkin boundary element computation of T-stress and stress intensity factors for mixed-mode cracks by the interaction integral method

An interaction integral method for evaluating T-stress and mixed-mode stress intensity factors (SIFs) for two-dimensional crack problems using the symmetric Galerkin boundary element method is presented. By introducing a known auxiliary field solution, the SIFs for both mode I and mode II are obtained from a path-independent interaction integral entirely based on the J(≡J₁) integral. The T-stress can be calculated directly from the interaction integral by simply changing the auxiliary field. The numerical implementation of the interaction integral method is relatively simple compared to other approaches and the method yields accurate results. A number of numerical examples with available analytical and numerical solutions are examined to demonstrate the accuracy and efficiency of the method.