A modified version of domain integral method is developed for evaluation of energy release rate with finite element solutions for problems with a 2-D crack located in a heterogeneous elastic field. The heterogeneous field considered in this work generally contains various materials, with discontinuous mechanical moduli across the interfaces. The formulation is proved to be patch-independent, in a generalized sense, and valid for problems under both small and large deformations. The results of calculation appear to be very insensitive to the crack tip finite element models when the tip is away from the material interface. However, strong dependency on the local modeling is observed in case the tip is located at the interface. Alternative studies on this particular case are thus required.
