The effect of dilatational and distortional strain energy density on crack initiation

Abstract

AbstractTo investigate the distinct influences of dilatational strain energy density (Dil‐SED) and distortional strain energy density (Dis‐SED) on crack initiation, quasi‐static loading tests were performed on centrally cracked polymethyl methacrylate samples, employing digital image correlation equipment. Our findings unveiled that the Dil‐SED promotes crack initiation, while the Dis‐SED inhibits it. Additionally, it was found that the direction obtained by the ratio of these two strain energy densities was closer to the crack initiation direction than the direction associated with the maximum Dil‐SED and minimum Dis‐SED values. Furthermore, experimental and finite element method (FEM) results indicated that the distribution of these two strain energy densities remains relatively insensitive to the core region's radius . By understanding Dil‐SED and Dis‐SED magnitudes and their impacts on crack initiation, material failure can be predicted and prevented.