Constitutive model for dynamic mechanical response of high strength steel

Abstract:

It’s important to understand the deformation behavior of metals in the dynamic loading process. In this study, the dynamic mechanical responses of high strength steel are investigated by uniaxial compressive experiments on the Split Hopkinson Pressure Bar (SHPB) with strain rate range from 3000 to 12000s-1 and temperature range from 20℃to 800℃. The experimental results show that the mechanical responses of steel investigated are strongly affected by the strain, strain rate and deformation temperature. The flow stress increases with the increasing of strain rate while decreases with the increasing of deformation temperature. A phenomenological constitutive model is established to describe the strain rate harden and temperature soften behavior. The stress-strain relationships predicted by the phenomenological constitutive model agree well with the experimental results, which shows that the proposed constitutive model can be used to study the dynamic deformation process furthermore.