Viscoplastic Modeling With Strain Rate-History Dependency

The strain rate-history effect on the plastic behavior of some classes of viscoplastic materials is incorporated into the power formula of Bodner’s model by adopting an integral-memory type equation for the “hardening” state variable. The modified model is incorporated into a finite element program. Results on uniaxial loading-unloading-reloading at different rates as well as jump tests show the capability of this modified model in simulating the strain rate-history effects on the yield stress and the plastic hardening for some viscoplastic materials.