High strain rate experiments and constitutive model for Q390D steel

Abstract

The Q390D steel is a structural steel with a low alloy content and high strength. Despite insufficient data from research on the Q390D steel, the demand for its use in engineering construction is steadily increasing. Tensile testing and an SHPB apparatus were used to study the mechanical properties of Q390D in this study. The behavior of a Q390D steel was investigated in this work at strain rates ranging from 0.0001 to 3000 s−1. Q390D had a significant rate of strain hardening. The dynamic intensity can be accurately predicted by fitting the Cowper-Symonds model. An original Johnson-Cook model had limited a low accuracy in predicting the stress–strain behavior at high strain rates. Improvements are proposed to the Johnson-Cook model so that it will predict the mechanical behavior reliably at high strain rates.