Interactions of coplanar surface semi-elliptical cracks and embedded elliptical cracks in finite thickness plates under uniform tension

This paper analyzes the interactions of coplanar surface semi-elliptical cracks and embedded elliptical cracks in a finite thickness plate under uniform tension, for which no numerical solutions appear to be available in the literature. The ratios of crack depth to crack length (b(1)/a(1) and b(2)/a(2)) are 0.25 and 1.0; the relative distances between two cracks (s(1)/b(min) and s(2)/b(min)) range from 0.5 to 2.0. Two kinds of interactions, interaction 1 for which neither the long principal axes nor the short principal axes of two cracks are collinear and interaction 2 for which the short principal axes of two cracks are collinear within a total of 48 crack configurations, are studied. The mode I stress intensity factors along the crack front and the interacting coefficient of two cracks are presented. The numerical results show that interaction 2 has a stronger interacting effect from interaction 1. The numerical analyses are carried out by the hybrid boundary elements method.