Stress Intensity Evaluation Formula for a Crack Parallel to an Interface by √area Parameter

Abstract

To evaluate arbitrary shaped defects or cracks parallel to an interface, a formula is proposed in terms of √area parameter for the maximum stress intensity factors. Here “area” is the projected area of the defect or crack. First, the results for an elliptical crack parallel to a bimaterial interface are considered with varying the distance, aspect ratio of the crack, and combinations of material's constants systematically. Second, the stress intensity factors of an interface crack and a crack in a functionally graded material are also investigated. It is found that the maximum stress intensity factors normalized by √area are almost independent of the crack aspect ratio. They are given in a form of formula useful for engineering applications.