Stress Intensity Factors of Interacting Parallel Surface Cracks

Abstract

Stress intensity factor (K value) is often used for evaluating the reliability of cracked structure. In this study, the K value of interacting parallel surface crack is calculated using the finite element method. A simplified mesh generation method is adopted in order to improve the complexity of mesh generating procedure. The influence of interaction between cracks on the magnitude of K is discussed based on the results under various conditions of relative location, aspect ratio and crack depth/ thickness ratio. For example, if the inner crack tips cross each other, K value is enhanced at the deepest point rather than the one near the surface. When cracks are close enough, the stress distribution is almost the same as that of a coalesced crack. Since the aspect ratio of a coalesced crack is smaller than that of the separated cracks, K value near the closest crack fronts is enhanced.