Stress intensity factor and interaction analysis of offset parallel cracks in brittle solids

Abstract

The analytical solutions for the mode-I and mode-II stress intensity factor (SIF) of arbitrary distributed offset parallel cracks in brittle solids were generated based on the Kachanov method and superposition principle. By analyzing the SIF ratio, effects of the horizontal interval, vertical interval, crack inclination angle and crack length on the interaction of offset parallel cracks were estimated, and the interference area of the crack was determined theoretically. Numerical models were established using the finite element method (FEM) to show the performance of the present method, and the relationship between crack propagation and crack interaction was discussed. The results show that the SIFs obtained from the present method agree well with the accurate ones. The interaction of offset parallel cracks contains three types, i.e. reinforcing effect, shielding effect and null-effect, which can convert mutually with the change in interval, crack inclination angle and crack length. The interference area of the crack can be divided into reinforcing, shielding area and null-effect area which are symmetric about the crack. The reinforcing effect facilitates crack propagation while the shielding effect inhibits crack propagation.