Significance of crack opening displacement and crack tip plastic strain energy in fracture initiation

Publisher Website
Google Scholar
Abstract
The development of an intense strain region, formed locally at a blunting crack tip, and the equivalent plastic strain distribution within it were investigated in terms of crack opening displacement δt by means of the recrystallization technique. The results obtained showed that the equivalent plastic strain within the region was given by ε¯p=ε¯0(δtcosθr′)m where r′ was distance from crack-tip-free surface and m was 0.6–0.7 in this study. Furthermore, based on the above expression, the density of plastic working and plastic work done within the intense strain region were calculated as a function of crack opening displacement. Demonstrating the importance of these parameters with reference to fracture initiation, both fibrous and cleavage, the significance of crack opening displacement was emphasized.