A New Interaction Integral Method for Nonhomogeneous Materials

Abstract

A new interaction integral technique is derived for computation of mixed-mode stress intensity factors (SIFs) in nonhomogeneous materials with continuous or discontinuous properties. This method is based on a conservation integral that relies on two admissible mechanical states (actual and auxiliary fields). In the equivalent domain formulation, the integrand does not involve any derivatives of material properties. Moreover, the formulation is proved to be still valid when the integral domain contains material interfaces. Therefore, its applicable range is greatly enlarged. The method is combined with the extended finite element method (XFEM) to calculate the SIFs for different integral domains. Numerical results show that the interaction integral has excellent convergence for material nonhomogeneity and discontinuity.