Intermediate strain rate constitutive modeling of gradient rolled vanadium-microalloyed pearlitic steel for bridge...

Ensuring the structural integrity of bridge cables under dynamic loads requires materials with stable strain-rate-dependent mechanical properties. This study investigates the rate-dependent tensile behavior and constitutive modeling of vanadium-microalloyed pearlitic steel processed via gradient rolling (10%-40% reduction) at intermediate strain rates (10^-4 to 1.3 s^-1). Experimental results show that synergistic strengthening from vanadium precipitation and gradient rolling achieves yield strengths exceeding 700 MPa and ultimate tensile strengths over 1,299 MPa. While gradient rolling maintains work-hardening capacity, elevated strain rates induce non-linear ductility loss due to a transition from dimple rupture to quasi-cleavage failure. To address these rate-dependent responses, a modified Johnson-Cook model incorporating a cubic polynomial coupling term was developed. This model provides accurate predictions for intermediate strain-rate stress-strain behaviors, offering a framework for the safety assessment and design of advanced bridge cable systems.