Deformation Responses and Fracture Behaviors of AA6061 under Different Stress Triaxialities

This study investigates the deformation responses and fracture behaviors of AA6061 under different stress triaxiality. Specimens of specific shapes and sizes are designed to achieve different stress triaxialities. Mechanical experiments and scanning electron microscopy analyses are performed to capture the mechanical behaviors and failure features of each specimen. Results show that thicker specimens deform more evenly in thickness than thinner specimens but exhibit slightly more brittleness, while the opposite is true for the notch radius of the specimens. Therefore, these two factors can be applied to the design of specimens for specific testing requirements. The failure mechanism is sensitive to the geometrical factors of the specimen. In addition, the distribution of failure features on the fracture surface is found to play a dominant role in the change in mechanism.