高强钢动态力学性能本构模型研究

Constitutive model for dynamic mechanical response of high strength steel

摘要:

为了研究高强钢材料在动态加载过程中的力学响应，采用分离式霍普金森压杆对材料进行了不同应变率（3000到 12000s-1）和不同温度（20℃到800℃）单轴压缩实验。实验结果表明：高强钢的动态力学行为受应变率和温度的强烈影响。流动应力随着应变率的升高而增加，随着温度的升高而降低。提出了一个经验型本构模型来描述材料的加工硬化和温度软化行为。该本构模型预测的应力——应变曲线与实验结构较好吻合，表明该本构模型可进一步用于高强钢动态变形过程的数值模拟研究。

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.