Abstract Uniaxial compression, uniaxial tension, and new double shear experimental methods are used to study the effect of stress state on the mechanical behaviors of Ti-6Al-4V over a wide range of strain rates (0.001-6500s−1). The experimental results show that strain rate and stress state both have strong influences on the plastic flow and failure properties of the material. With an increasing strain rate, the work-hardening rate increases under uniaxial compression loading, but decreases under uniaxial tension and shear. Moreover, with the increase of strain rates, the initial failure strain increases under uniaxial tension, but decreases under the uniaxial compression conditions. Based on the experimental results, the Johnson-Cook (JC) hardening laws are used in finite element analysis (FEA) to simulate the mechanical responses of the material. It shows that the simulated results and the experimental data are in good agreement. The results indicate that the effects of strain rate and stress state should be considered in the constitutive model. Fractographic examinations are also conducted under different loading conditions. The failure processes of the material are controlled by different micro-mechanisms.

中文翻译：

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应变速率和应力状态对Ti-6Al-4V合金力学性能的影响

摘要 采用单轴压缩、单轴拉伸和新的双剪切实验方法研究了应力状态对大应变速率范围 (0.001-6500s-1) 内 Ti-6Al-4V 力学行为的影响。实验结果表明，应变率和应力状态对材料的塑性流动和破坏性能都有很大的影响。随着应变率的增加，加工硬化率在单轴压缩加载下增加，但在单轴拉伸和剪切下下降。此外，随着应变速率的增加，初始破坏应变在单轴拉伸下增加，但在单轴压缩条件下减小。根据实验结果，Johnson-Cook (JC) 硬化定律用于有限元分析 (FEA) 以模拟材料的机械响应。表明模拟结果与实验数据吻合较好。结果表明，本构模型应考虑应变速率和应力状态的影响。断口检查也在不同的负载条件下进行。材料的失效过程由不同的微观机制控制。