Analytical stress intensity factors and J k ‐integrals of periodic and collinear interface cracks between dissimilar orthotropic materials

This paper introduces an analytical expression for the stress intensity factors at the crack tips of a row of periodic and collinear cracks between infinite dissimilar orthotropic materials. The analytical J k ‐integrals of these traction‐free cracks have been presented for different material combinations, ‘crack length’/‘interval width’ ratios ( λ ) and various in‐plane loading conditions. Some of the analytical J k ‐integrals have been compared with the numerical values computed using the boundary element crack shape sensitivities which are in good agreement. For any in‐plane loading condition of a bimaterial plate with periodic and collinear interface cracks, the normalised J 1 ‐integral is almost independent of λ , but there is a slight variation in the normalised J 2 ‐integral with respect to λ . This is provided that the normalising factor is the strain energy release rate of a homogeneous plate made from one of the materials with the same ratio of λ and subject to the same loading condition.