(1. 內(nèi)蒙古科技大學 土木工程學院，包頭 014010；
2. 上海市應用數(shù)學和力學研究所，上海 200072)
摘 要: 采用電子萬能試驗機對TC18合金進行常溫準靜態(tài)壓縮實驗，得到合金在準靜態(tài)下的實驗數(shù)據(jù)，根據(jù)實驗數(shù)據(jù)，選用分離式Hopkinson壓桿對TC18合金在溫度分別為298 K、523 K、773 K和1023 K，應變率分別為500 s-1、1000 s-1和1500 s-1下進行動態(tài)力學性能實驗，得到合金在高溫動態(tài)壓縮條件下的應力-應變曲線。在Johnson-Cook模型的基礎上，通過考慮應變、應變率和溫度的耦合效應，建立修正的Johnson-Cook模型對TC18合金的高溫動態(tài)力學性能進行表征，模型預測結(jié)果與實驗結(jié)果吻合良好，表明修正的Johnson-Cook模型能夠更精確地表征TC18合金在高溫下的流動應力。
關鍵字: TC18合金；Hopkinson壓桿；Johnson-Cook模型；高溫；動態(tài)
（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
