Effect of tensile stress gradient on brittle fracture initiation

Abstract The problem of tension fracture initiation from a few types of voids and cracks subjected to compressive loading is examined theoretically and experimentally. It is shown that equality between maximum tensile stress concentration and the uniaxial tensile strength is a necessary but not an adequate condition for fracture initiation. The fracture initiation stress depends to a greater degree on the stress gradient along the fracture path. A simple theory is proposed which incorporates both the maximum stress concentration and the stress gradient.