Mechanical behavior of a multifunctional titanium alloy Gum Metal was investigated by conducting tensile tests at various strain rates and applying digital image correlation (DIC) technique. Stress–strain curves confirmed low Young’s modulus and high strength of the alloy. The determined values of yield strength had a tendency to increase, whereas the elongation to the specimen rupture tended to decrease with increasing strain rate. True stress versus strain curves were analyzed using selected lengths of virtual extensometer (VE) placed in the strain localization area. When the initial length of the VE was the same as the gauge length, work hardening was observed macroscopically at lower strain rates, and a softening was seen at higher strain rates. However, the softening effect was not observed at the shorter VE lengths. Evolution of the Hencky strain and rate of deformation tensor component fields were analyzed for various strain rates at selected stages of Gum Metal loading. The DIC analysis demonstrated that for lower strain rates the deformation is macroscopically uniform up to the higher average Hencky strains, whereas for higher strain rates the strain localization occurs at the lower average Hencky strains of the deformation process and takes place in the smaller area. It was also found that for all strain rates applied, the maximal values of Hencky strain immediately before rupture of Gum Metal samples were similar for each of the applied strain rates, and the maximal local values of deformation rate were two orders higher when compared to applied average strain rate values.

中文翻译：

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利用数字图像相关研究口香糖金属在张力下的应变率敏感性

通过在各种应变速率下进行拉伸测试并应用数字图像相关（DIC）技术，研究了多功能钛合金口香糖的力学行为。应力-应变曲线证实了该合金的低杨氏模量和高强度。所确定的屈服强度值具有增加的趋势，而随着应变率的增加，至样品断裂的伸长率倾向于降低。使用放置在应变局部区域中的虚拟引伸计（VE）的选定长度来分析真实应力与应变的关系曲线。当VE的初始长度与标准长度相同时，在较低的应变速率下宏观观察到加工硬化，而在较高的应变速率下观察到软化。然而，在较短的VE长度下未观察到软化作用。分析了在口香糖金属加载的选定阶段的各种应变速率下的Hencky应变的演变和变形张量分量场的速率。DIC分析表明，对于较低的应变率，直到宏观平均Hencky应变，变形在宏观上是均匀的；而对于较高的应变率，应变局部化发生在变形过程的平均Hencky较低的应变，并且发生在较小的区域。还发现，对于所施加的所有应变速率，对于每个所施加的应变速率，刚好在口香糖金属样品破裂之前的Hencky应变的最大值都相似，并且与施加的应变速率相比，变形率的最大值局部值高两个数量级。平均应变率值。