Enhancement in the Modeling of Temperature and Strain Rate-Dependent Plastic Hardening Behavior of a Sheet Metal

Abstract

In the present study, viscoplastic hardening behavior of aluminum alloy 3003 sheet was measured and existing hardening models were evaluated in terms of the accuracy for predicting strain rate and temperature-dependent flow behaviors. Moreover, a modified hardening model was proposed to capture the flow stress-strain responses under various strain rates and temperatures with enhanced accuracy. Mechanical responses of the material were measured by using uniaxial tensile test at various temperature (approximate to 25-250 degrees C) and strain rates (approximate to 0.001-0.3 s(-1)), and the split Hopkinson pressure bar (SHPB) test was also conducted to obtain flow behavior at the strain rate over 700 s(-1) at room temperature. Based on these experimental data, two well accepted viscoplastic constitutive models-Johnson-Cook and Khan-Huang-Liang-were evaluated. Finally, the Hollomon/Voce type model was further developed, which resulted in significant improvement in predicting the flow stress curves under wide range of strain rate and temperature.