(1. 北京科技大学 材料科学与工程学院，北京 100083；
2. 中国兵器装备集团公司 西南技术工程研究所，重庆 400039)
摘 要: 利用Gleeble1500热模拟试验机和分离式霍普金森压杆试验装置(SHPB)对T2铜进行常温下准静态压缩试验和高应变率下的冲击压缩实验, 获得不同应变率下的应力-应变曲线。结果表明:T2铜在动态冲击下的强度明显高于准静态压缩下的强度，具有显著的应变率强化效应；在动态冲击较低应变速率的区域内，T2铜的塑性流动应力对应变率很敏感，具有明显的应变强化和应变率强化效应。但在动态冲击较高应变速率的区域内，发生相同变形时的应力水平相差不大，表现出对应变率变化不敏感的性质。对传统的Johnson-Cook本构模型进行修正，拟合曲线与试验曲线吻合较好。
关键字: T2铜；霍普金森压杆试验；应变率效应；本构模型
（1.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. Southwest Technology and Engineering Research Institute,
China South Industries Group Corporation, Chongqing 400039, China）
Abstract:The quasi-static compression and impact experiment under high strain rates of the T2 copper were carried out at room temperature by the Gleeble1500 thermal simulation testing machine and high split Hopkison pressure bar (SHPB) testing technique. The stress-strain curves of materials at different strain rates were obtained. The experimental results show that the strength of T2 copper under dynamic impact is obviously higher than that under quasi-static compression and the strain rate strengthening effect is significant. In the lower strain rate region of the dynamic impact, the plastic flow stress of T2 copper is very sensitive to strain rate, and it has obvious strain hardening and strain rate hardening effect. But in the higher strain rate region of the dynamic impact, the stresses under the same strain are not quite different and they are not sensitive to strain rates. The traditional Johnson-Cook constitutive model is modified to make the fitting curves agree well with the test curves.
Key words: T2 copper; split Hopkison pressure bar test; strain rate effect; constitutive model
