船用EH690钢动态力学性能与本构关系

Dynamic Mechanical Properties and Material Constitutive Relationship of Marine EH690 Steel

文章使用静态试验机和分离式霍普金森杆(SHPB)装置,研究船用EH690超高强度钢的动态力学性能并获得了材料本构方程。在应变率为2.5×10^(−4)/s时,通过准静态试验验证了准静态力学性能;在应变率为450/s~4260/s时,通过冲击试验得到了动态冲击下的应力-应变曲线。基于试验数据对Cowper-Symonds材料模型进行修正,得到本构参数和修正后的本构关系,证明了模型的适用性。结果表明,船用EH690钢的应变率强化效应和非线性应变硬化效应明显,修正后动态本构关系可以描述船用EH690钢在冲击荷载下的力学性能。

Static testing machine and SHPB device are used to study the dynamic mechanical properties of Marine EH690 ultra-high strength steel and obtain the material constitutive equation.The quasi-static mechanical properties are verified by the quasi-static experiment at strain rate 2.5×10^(−4)/s.The stress-strain curves under dynamic impact are obtained by impact tests in the strain rate range of 450/s~4260/s,two parameters of constitutive relations and modified constitutive relations of Cowper-Symonds model are obtained based on the experimental data,the applicability of the modified model is proved.The results show that the strain rate strengthening effect and nonlinear strain hardening effect of marine EH690 steel are obvious,and the modified dynamic constitutive relationship can describe the mechanical properties of Marine EH690 steel under impact load.