The determination of constitutive relation from the miniature tensile test is of high interest in multiple areas. Here, a convenient experimental method is proposed to determine the true stress–strain curve from the miniature tensile test. The instantaneous cross-sectional area is estimated by only one camera in aid of digital image correlation technique. This method was applied on commercial pure titanium and aluminum 6061 alloys, and the results indicate that the extracted true stress–strain curves are not scale-dependent. The derived mechanical properties from miniature specimens match well with the results of standard specimens. The correctness of the true stress–strain curve was evaluated by the finite element analysis method. The results suggest that the derived true stress–strain curve is capable to represent the constitutive behavior of the tested materials.

中文翻译：

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用数字图像相关的微型拉伸试验确定本构关系

从微型拉伸试验中确定本构关系在多个领域都受到高度关注。在这里，提出了一种方便的实验方法来确定微型拉伸试验的真实应力-应变曲线。借助数字图像相关技术，仅由一台相机估计瞬时横截面积。该方法应用于商用纯钛和铝 6061 合金，结果表明提取的真实应力-应变曲线与比例无关。微型试样的衍生机械性能与标准试样的结果非常吻合。通过有限元分析方法评估真实应力-应变曲线的正确性。