Micromechanics-based modeling of plastic and ductile fracture of aluminum alloy 2024-O

Abstract

In this study, the plastic deformation behavior at a large strain range, as well as the ductile damage and fracture of aluminum alloy 2024-O materials, were investigated under quasi-static conditions. The plasticity of the material, including a large deformation, was characterized by conducting uniaxial tension and balanced-biaxial bulging tension tests. This condition was reproduced using the Hershey-Hosford nonquadratic isotropic plastic yielding criterion and combined Hollomon/Voce strain-hardening model. The ductile damage and fracture were analyzed using notched plane strain and in-plane shear experiments by incorporating a wide range of stress states. Finally, multiaxial Nakajima tests with a round sphere punch were conducted to assess the material formability. Simultaneously, finite element predictions of the ductile fracture behavior were performed using micromechanics-based material models, such as modified Gurson-Tvergaard-Needleman (GTN) and Hosford -Coulomb models. The force-displacement characteristics and surface strain distributions measured using the experimental approach were compared with the simulated results. The results indicated that the modified GTN model provided better prediction of plasticity and ductile damage behavior of aluminum alloy 2024-O materials.