Orientation-dependent shear mechanical responses and failure mechanisms of AA6061

Abstract

The orientation-dependent shear responses were investigated in present paper through the combinations of mechanical test, digital image correlation (DIC) technique, and morphology characterizations. Results demonstrate that material orientation has a negligible effect on the elastic behavior of AA6061-T6 under shear loading, but significantly influences its inelastic behavior, including initial yielding, hardening, and fracture. Specifically, the 45°-oriented shear specimen exhibits the lowest yield strength (136.8 MPa), highest hardening modulus (48.49 MPa), and largest fracture strain (0.288). These differences primarily originate from the material's initial texture. Correspondingly, the fracture characteristics reveal that the 45°-oriented specimen possesses the largest dimple size with an aspect ratio of 1.55, which is approximately 6.4 % and 5.8 % higher than those of the 0° and 90° shear specimens, respectively. This indicates the most pronounced shear-induced dimple features.