Mixed mode ductile fracture of an anisotropic 2024 Al-Cu alloy

Abstract : Assessment of structural integrity of structures often requires investigating the combination of tensile(Mode I) and shearing (Mode II) or tearing (Mode III) loadings. The purpose of this study is to shed some lighton the ductile mixed-mode fracture process and its underlying mechanics. Ductile rupture of a 2024 Al Alloy thinsheet is investigated under mixed-mode loading. Mechanical tests are carried out on smooth and specific mixedmodeArcan specimens. Test data on smooth samples are used to identify the parameters of constitutive equations describing plastic anisotropy. Digital image correlation (DIC) technique is used to measure the local displacement in the vicinity of the V-notch. Using these measurements an analysis of the effect of mixed-mode loading onductile crack initiation is performed. Failure mechanisms are investigated using scanning electron microscope(SEM). Results are finally interpreted and modeled using a simple local approach based on the Rice and Traceycriterion.