Resistances of non-flat cracks and their relation to crack compliances

Cracks of non-flat geometries are common in materials science applications. The effect of non-flatness on crack resistances is analyzed by examining several non-flat patterns, such as “waviness” and “caps”. Non-flatness increases the resistance component normal to the crack and gives rise to the transverse component. At small-to-moderate non-flatness, these effects are relatively weak, but they become substantial for strongly non-flat cracks. We suggested an approximation that covers all non-flat geometries, by replacing a given crack by a set of flat circular ones, and examined its accuracy. We also examined the effect of non-flatness on the cross-property connection that relates changes in the elastic and conductive properties due to cracks.