Numerical modeling and constitutive model verification for high-strength automotive steel

In this paper, the quasi-static and dynamic tensile tests with a gauge length of 20 mm for dual-phase (DP) 780 steel were conducted under strain rates ranging from 10(-3) to 10(3)/s. The neglected details and differences between the quasi-static and dynamic tensile test conditions were investigated to develop an accurate numerical modeling method. A high-precision combination method for the empirical constitutive model was proposed and utilized in the developed numerical model to verify the ability of the constitutive model to reproduce the experimental data at different strain rates. The excellent results indicate that the adjusted determination coefficient of the constitutive model, the adjustable range of the extrapolation curves, and the proportion factor P in the combined constitutive model are the key parameters for accurately describing the quasi-static and dynamic mechanical behavior before and after the necking.