高伸长率QP钢在高应变速率下的力学特性  

Mechanical properties on high elongation steel QP under high strain rate

作　　者：连昌伟[1,2] 陈新平[1,2] 俞宁峰[1,2] 

机构地区：[1]宝山钢铁股份有限公司研究院,上海201900 [2]汽车用钢开发与应用技术国家重点实验室(宝钢),上海201900

出　　处：《锻压技术》2017年第7期163-168,共6页Forging & Stamping Technology

基　　金：国家重点研发计划课题(2016YFB0101605)

摘　　要：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 investigate mechanical properties of high elongation steel QP under dynamic load,for two different levels of steel QP,the uniaxial tensile test was conducted under conditions of quasi-static and high strain rate,and strain-stress curves under different strain rates were obtained.Through the analysis of experimental data,the relationship between stress and strain rate was studied,and a dynamic constitutive model was proposed to describe the dynamic mechanical properties of steel QP.For hat-shape beam made by QP980,its model was established by Hyper Works,and the axial crushing process was simulated by LS-DYNA.Then,simulation results and actual collision test results were compared and verified.It is found that steel QP has a strain rate effect obviously,and the strain rate hardening is not in linear relationship with the relative strain rate.According to the comparison of axial crushing test and numerical simulation for hat-shape beam,the dynamic mechanical properties of steel QP under different strain rates are well described by the modified John-Cook model.

关 键 词：QP钢 高速拉伸 动态力学特性 应变速率 本构模型 

分 类 号：TG142.1[一般工业技术—材料科学与工程]