The modified temperature term on Johnson-Cook constitutive model of AZ31 magnesium alloy with {0002} texture

Abstract

The dynamic compression experiments with Split-Hopkinson Pressure Bar(SHPB) were performed on AZ31 magnesium alloy rolled sheet specimens in the normal direction (AZ31-ND) with {0002} texture at the temperature of 293–523 K and the strain rate of 0.001–2200 s−1. The temperature term in Johnson-Cook(JC) constitutive model had been reasonably modified. This advantage made constitutive model promising for decribing the dynamic deformation behavior of AZ31-ND with {0002} texture more accurately. The obtained true stress-true plastic strain curves agreed well with the measured results in a wide range of strain rates and temperatures. The thermal softeninging, strain and strain rate hardening effect on the AZ31-ND with {0002} texture were discussed. The adiabatic shear band (ASB) of AZ31-ND with {0002} texture hat shaped specimen was successfully predicted by combining modified JC constitutive model and numerical simulation, which was also validated by Electron Back-Scattered Diffraction (EBSD) map under the same boundary condition. Keywords: Modified Johnson Cook constitutive model, AZ31-ND with {0002} texture, Dynamic compression, Numerical simulation, Adiabatic shear band