Abstract
In this paper, we investigate crack extension behavior for a linear elastic body with a parallel interacting crack which interrupts the extension of a main crack. We discuss the crack extension behaviors based on maximum energy release rate criterion. We compute the energy release rate at the onset of crack kinking, of all the crack tips, using the E-integral which is path independent even for a path containing stationary crack tips. As a result, assuming the isotropy of fracture toughness of the body, we find the optimum position of interacting crack that interrupts the extension of a main crack, and find the energy release rate that tensile fracture strength of the body becomes the largest.
