Numerical and Experimental Analyses of the Effect of Negative Stress Triaxialities on Ductile Damage and Failure

Abstract

AbstractThe paper deals with an experimental and corresponding numerical series of the biaxial Z‐specimen, which is made of an aluminum alloy, to investigate the effect of negative stress triaxialities on ductile damage and failure, which are stress‐state‐dependent. Therefore, the continuum model contains a stress‐state‐dependent damage condition and a stress‐state‐dependent damage rule to describe the damage and failure mechanisms. In the experimental evaluation, in addition to force‐displacement curves, optical investigations such as digital image correlation (DIC) and scanning electron microscopy (SEM) were used. The results showed that with compression‐shear load fracture occurs at greater negative triaxialities than previously known. Therefore a new function for the cut‐off value of stress triaxiality is proposed.