TA1本构模型的确定

Determination of TA1 constitutive relation

采用试验方法,通过准静态压缩试验和分离式Hopkinson压杆试验,获得不同应变率10-3s-1～103s-1和不同温度293K～873K范围内TA1的应力-应变曲线;基于Johnson-Cook模型对试验结果进行分析,并对其应变率强化项做出修正。结果表明,TA1为应变率敏感材料,流动应力随应变率增加而增加,随温度增加而减小;未经修正的Johnson-Cook本构模型与试验数据偏差较大,修正后的本构模型与试验值吻合较好。

The stress-strain curves of TA1 under different strain rate ranges （10^ 3 s-1 -10^3 s-1） and different temperature ranges （293K-873K） were obtained through the quasi-static compression test and split Hopkinson pressure bar test. The parameters of Johnson-Cook model were determined and the strain rate hardening term was modified. The results showed that TA1 was a kind of strain-rate sensitive materials. The flow stress increased with the increase of strain rate, while decreased with the increase of temperature. The un-amended Johnson-Cook constitutive relation had a large deviation from the test data. The modified constitutive relation had a good agreement with experimental results.