On Cracking Instability in Plates Containing Circular Holes

Abstract

For functional reasons, most engineering structures contain geometrical discontinuities such as notches, fastener/rivet holes, etc. This paper describes an investigation into the effect of multiple circular holes on the stability condition of cracked plates.

The cracked plates chosen for the investigation contained two circular holes placed immediately above and below a crack. The plate height (H) and width (W) ratio used was 0.730. At this ratio an isolated crack without the presence of holes had been found to be unstable. For the cracked geometry with the holes, the stability conditions were found to be governed not by the geometrical plate ratio (i.e., H/W) as in the case of an isolated crack, but by the ratio of the crack length and hole radius (a/R). The prediction that stable crack growth can be attained for the a/R ratio, about 1.3, agreed fully with the experimental observations.