Crack initiation and propagation in materials with randomly distributed holes

We investigate fracture of both elastic-brittle (epoxy) and ductile (aluminum) sheets, each containing circular holes, and subjected to a uniaxial tension. The holes are distributed at random but with a restriction of no overlap and a minimum separation distance. In this study, which includes both numerical and experimental results, we consider a single configuration of holes but several samples and find that crack paths in these perforated sheets are not unique. This illustrates the need for a stochastic fracture mechanics analysis for this class of problems.