Study on Constitutive Model and Fracture Criterion of 7075 Aluminum Alloy at High Temperature

7075 aluminum alloy is prone to failures like wrinkling and cracking during hot forming. Therefore, it is particularly important to establish a correct material model that can accurately reflect the deformation and fracture of the material. In this study, Tensile tests were conducted on the specimens at different temperatures, and Digital Image Correlation (DIC) was employed to obtain the specimen strain. The anisotropic yield criterion and the DF2014 fracture criterion were calibrated based on experiments and modeling, which were then used to characterize the anisotropy and fracture behavior of 7075 aluminum alloy, respectively. As the experiments and simulation results revealed, the 7075 aluminum alloy still had a more pronounced anisotropy at high temperatures. Finite element simulation was performed to obtain the parameters of the DF2014 fracture model at different temperatures. The results showed that the DF2014 fracture model could accurately predict the fracture behavior of the aluminum alloy. The specimens exhibited brittle fracture at room temperature, while the behavior changed to typical ductile fracture as the temperature rose.