(1. 内蒙古科技大学 土木工程学院，包头 014010；
2. 上海市应用数学和力学研究所，上海 200072)
摘 要: 采用电子万能试验机对TC18合金进行常温准静态压缩实验，得到合金在准静态下的实验数据，根据实验数据，选用分离式Hopkinson压杆对TC18合金在温度分别为298 K、523 K、773 K和1023 K，应变率分别为500 s-1、1000 s-1和1500 s-1下进行动态力学性能实验，得到合金在高温动态压缩条件下的应力-应变曲线。在Johnson-Cook模型的基础上，通过考虑应变、应变率和温度的耦合效应，建立修正的Johnson-Cook模型对TC18合金的高温动态力学性能进行表征，模型预测结果与实验结果吻合良好，表明修正的Johnson-Cook模型能够更精确地表征TC18合金在高温下的流动应力。
关键字: TC18合金；Hopkinson压杆；Johnson-Cook模型；高温；动态
（1. School of Civil Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, China;
2. Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072, China）
Abstract:A quasi-static compression experiment at room temperature was performed on the TC18 alloy using an electronic universal testing machine to obtain the experimental data of the alloy under quasi-static conditions. According to the experimental data, the dynamic mechanical properties of TC18 alloy at 298 K, 523 K, 773 K and 1023 K with strain rates of 500 s-1, 1000 s-1 and 1500 s-1 were tested using a split Hopkinson pressure bar. And the stress-strain curve of the alloy under dynamic compression at high temperatures was obtained. Based on Johnson-Cook model, considering the coupling effects of strain, strain rate and temperature, a modified Johnson-Cook model was established to characterize the high temperature dynamic mechanical properties of TC18 alloy. The predicted results are in good agreement with the experimental results, indicating that the modified Johnson-Cook model can more accurately characterize the flow stress of TC18 alloy at high temperature.
Key words: TC18 alloy; split Hopkinson pressure bar; Johnson-Cook model; high temperature; dynamic state
