A novel constitutive model for Ti-6Al-4V alloy based on dislocation pile-up theory

作者:Zhou, Tianfeng; Wu, Junjie; Liang, Zhiqiang*; Che, Jiangtao; Zhang, Yichuan; Wang, Xibin
来源:Materials Science and Technology, 2017, 33(11): 1379-1387.
DOI:10.1080/02670836.2017.1295512

摘要

The mechanical properties of the titanium alloy Ti-6Al-4V, which vary with the specimen size under different temperatures, are studied through the Split Hopkinson Pressure Bar (SHPB) test and the quasi-static tensile test to determine the parameters for the classical Johnson-Cook (JC) constitutive model. Based on the dislocation pile-up theory, the classical JC constitutive model is modified by adding a grain strain term Delta sigma to consider the influence of grain size. The SHPB and tensile tests are analysed using a finite element method simulation. Compared with the experimental results, the simulation results based on the modified JC model exhibit a much higher calculation accuracy than that of the classical JC model.