Dynamic tensile behavior of S690 high-strength structural steel at intermediate strain rates

This paper investigates the rate-dependent behavior of S690 high-strength structural steel at intermediate strain rates. Experimental tests consisting of seven groups of specimens were first conducted, and stress-strain curves at different intermediate strain rates were obtained. The tests indicated that the strain rate had an obvious influence on the behavior of S690 steel, i.e., both the yield stress and tensile strength increased remarkably with increasing strain rate. The test results were then used to determine the coefficients of two commonly used rate-dependent models, i.e., the Cowper-Symonds (C-S) model and the Johnson-Cook (J-C) model. A new modified J-C model was also proposed to predict the true stress-strain behavior of S690 steel at intermediate and high strain rates (up to 4109 s⁻¹). The accuracy of the proposed models was verified by comparing them with test results.