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为研究高伸长率QP钢的动态力学特性,以两种强度级别的QP钢为研究对象,进行准静态和高应变速率下的单向拉伸试验,得到了不同应变速率下的应力-应变曲线。通过对试验数据的分析,研究了应力与应变速率的关系,并提出动态本构模型来描述QP钢的动态力学特性。基于QP980制作的帽型梁零件,使用HyperWorks进行建模,使用LS-DYNA进行模拟轴向压溃过程的计算,并与实际碰撞试验结果进行对比和验证。通过分析发现:QP钢具有明显的应变速率效应,而且应变速率硬化与相对应变速率不呈线性关系。QP钢帽形梁碰撞试验与仿真对比表明,使用修正的Johnson-Cook模型能较好地描述QP钢在不同应变速率下的动态力学特性。
In order to study the dynamic mechanical properties of QP steel with high elongation, two kinds of QP steels with different strength grades were selected as the research object. The uniaxial tensile tests at quasi-static and high strain rates were carried out. The stress-strain curve. Through the analysis of experimental data, the relationship between stress and strain rate was studied, and the dynamic constitutive model was proposed to describe the dynamic mechanical properties of QP steel. Based on QP980, the hat-beam parts were modeled by using HyperWorks and LS-DYNA was used to simulate the process of axial crushing. The results were compared with the actual crash test results. The results show that QP steel has obvious strain rate effect, and the strain rate hardening is not linear with the relative strain rate. The comparison between QP steel hat-beam crash test and simulation shows that the modified Johnson-Cook model can better describe the dynamic mechanical properties of QP steel at different strain rates.