基于修正CS模型的船用低碳钢动态力学性能研究

为了得到船用低碳钢的动态力学性能及本构关系,运用静态试验机及分离式Hopkinson压杆加载装置,在应变率为0.000 2~3 900 s-1范围内得到了准静态拉伸及动态压缩条件下的应力应变曲线,对Cowper-Symonds材料模型进行了修正,得到了两种形式的本构关系,并讨论了模型的适用性。结果表明:船用低碳钢具有明显的应变率强化效应和非线性应变硬化效应;两种动态本构关系可以描述材料在冲击荷载下的力学性能;模型在高应变率(2 000 s-1)下的使用应慎重。

Dynamic mechanical behavior of low-carbon steel on improved Cowper-Symonds models

The σ-ε relation of ship low-carbon steel under different strain rates (0.000 2~3 900 s-1) was studied experimentally with the MTS (Materials test system) and the split Hopkinson press bar (SHPB), two improved Cowper-Symonds models and the parameters were obtained, and then the applicability of the models was investigated. The experimental results show that the low-carbon steel has a remarkable strain rate effect and a nonlinear strain hardening effect. Dynamic constitutive model of ship low-carbon steel can describe the dynamic mechanical behaviors under high strain rate. Application of the CS models should be careful when strain rate is higher than 2 000 s-1.