Dynamic tests and constitutive model for 7075-T6 aluminum alloy

Dynamic tests for 7075-T6 aluminum alloy under quasi-static, medium strain rate and high strain rate were performed by using an electronic universal testing machine a high velocity hydraulic servo-testing machine and a split Hopkinson tensile bar (SHTB) at room temperature. Stress-strain curves under different strain rates were obtained. The experimental results showed that the strain rate hardening effect of 7075-T6 aluminum alloy is obvious; the necking phenomenon of specimens' fracture is more remarkable with increase in strain rate. A Johnson-Cook constitutive model reflecting strain rate hardening effect of 7075-T6 aluminum alloy was fitted. The term of strain rate hardening in Johnson-Cook equation was modified to make the fitted results agree better with the test ones.