中文摘要：

对汽车用高强钢DP600在10^-4s^-1～10^3s^-1应变率范围内进行力学拉伸实验，在此基础上，采用唯象的方法对Khan-Huang本构模型进行修正建立DP600考虑率敏感效应的本构模型，对高应变率下试样的拉伸过程进行数值模拟验证模型有效性．结果表明，高强钢常温下具有明显的应变率敏感特性，高应变率下材料的屈服应力接近低应变率下的两倍．对Khan-Huang本构模型进行修正后可以比较准确地描述材料在不同应变率下力学行为，且参数容易确定，便于在有限元软件中实现接口，因此该模型可进一步应用于汽车的碰撞安全数值仿真中．

英文摘要：

Uniaxial quasi-static and dynamic tensile tests have been performed to study the rate-dependent mechanical behavior of dual phase steel 600 （DP600） widely used in the automotive industry. The phenomenological rate-dependent constitutive model based on Khan-Huang model has been established. The validify of the model has been proven throngh simulating the tensile process of DP600 specimens at high strain rates. The results show that the DP600 is very sensitive with the strain rate. The yield stress at high strain rates is almost twice as that at low strain rates. The modified Khan-Huang constitutive mod- el can describe the mechanical behaviors of DP600 at strain rate range 10^-4s^-1 to 10^3s^-1 perfectly. And this model can be coded with FEA software easily. Therefore, it can be used in the simulation on crash of automobiles.