Effect of notch radius on anisotropic fracture response of AA6061-T6 under tension process

The investigation of anisotropic fracture behavior is crucial in sheet metal application. A developed hybrid experimental-numerical method was proposed to investigate the anisotropic fracture response of AA6061-T6 sheet metal. Fracture tests of smooth and notched tensile specimens in combination with different material orientations were performed. The digital image correlation (DIC) technique and the finite element method (FEM) were applied synchronously to investigate the developed hybrid experimental-numerical method. This framework provides an approach to quantificationally analyze the relationship between local strain and stress triaxiality. The results showed that the ductility of 45° was the largest due to the marked necking before fracture. The equivalent fracture plastic strain of the smooth and notched specimens increased with the decrease in the initial stress triaxiality. With the effect of anisotropy, the different necking modes led to different plastic flows and local deformation. Then, those resulted in the different anisotropic fracture responses during the tension process.