室温高应变率下钛合金TA31流动应力响应行为及本构模型研究

Rheological behaviours and constitutive models for titanium alloy TA31 at room temperature and high strain rate

室温下,通过UTM5305万能试验机、ALT1000剖分式Hopkinson压杆装置,对钛合金TA31进行了准静态压缩、动态冲击试验。基于试验获得的应力-应变曲线,探讨了其应变硬化效应、应变率强化效应和绝热温升软化效应。依据钛合金TA31所呈现的流动应力响应行为特征,建立了一种新型J-C本构模型,该模型考虑了应变、应变率间的耦合作用和绝热温升对其流动应力的影响。将本构模型计算值与试验值进行对比分析,并借助相关系数(R)、平均相对误差(AARE)两个统计参数,评估了所建立的本构模型预测精度。R和AARE分别为0.988 7、0.63%,结果表明,所建立的新型J-C本构模型能够较准确地描述钛合金TA31的流动应力响应行为。

At room temperature,quasi-static compression and dynamic impact tests were conducted on titanium alloy TA31 by using UTM5305 universal testing machine and ALT1000 split Hopkinson pressure bar device.Based on the stress-strain curves attained from experiments,the strain hardening effect,strain rate strengthening effect,and adiabatic temperature rise softening effect were discussed.Based on the flow stress response characteristics of titanium alloy TA31,a new J-C constitutive model was established,which considers the coupling effect between strain and strain rate,as well as the influence of adiabatic temperature rise on its flow stress.The calculated values of the constitutive model were compared with the experimental values,and the prediction accuracy of the established constitutive model was evaluated by using two statistical parameters:correlation coefficient(R)and average relative error(AARE).The R and AARE of the model are 0.9887 and 0.63%,respectively.The results show that the new established J-C constitutive model can accurately describe the flow stress response behavior of titanium alloy TA31.