基于J-C模型的TC18钛合金动态本构方程构建

Establishment of Dynamic Constitutive Equation for TC18 Titanium Alloy Based on J-C Model

采用电子万能试验机对TC18钛合金进行常温准静态压缩实验,得到该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钛合金在温度分别为298、523、773、1 023 K,应变率分别为500、1 000、1 500 s^(-1)下进行动态力学性能实验,从而获得TC18钛合金在高温动态压缩条件下的应力-应变曲线,并利用J-C模型对合金在高应变率下的动态塑性本构关系进行拟合,最终建立该合金在高温下的动态塑性本构方程。通过对模型的计算结果分析表明,该模型可以较好地预测TC18钛合金在高温与冲击载荷共同作用下的塑性流变应力。

A quasi-static compression experiment at room temperature was performed on the TC18 titanium 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 titanium alloy at 298 K,523 K,773 K and 1 023 K with strain rates of 500 s-1,1 000 s-1 and 1 500 s-1 were tested using a split Hopkinson pressure bar.And the stress-strain curves of the alloy under dynamic compression at high temperatures were obtained.Based on the above experimental data,the J-C model was used to fit the dynamic plastic constitutive relation of the alloy under high strain rate.Finally,the dynamic plastic constitutive equation of the alloy at high temperature was established.The analysis of the model results show that the model can predict the plastic flow stress of TC18 titanium alloy under high temperature and impact load.