The errors of digital image correlation (DIC) method were systematically analyzed. Based on rigid-body motion, both the numerical and experimental errors related to DIC were investigated, and the influence of out-of-plane displacement was analyzed theoretically. In order to verify the accuracy of the home-developed DIC technique, the DIC method was compared with the strain gauge by measuring the same strain on a large copper specimen under tension. The result of the analysis indicates that the errors were originated from the noise of digital camera and the out-of-plane displacement of the whole measurement system. The system error was then calibrated and a better result was obtained.%对数字图像相关(DIC)方法的拉伸实验误差进行了系统分析.通过刚体运动实验,从软件模拟计算和硬件两方面研究了DIC方法的实验误差,同时,根据成像原理,分析了离面位移对实验结果的影响.为了检验测试系统的测量精度,将DIC方法与多晶铜试样拉伸实验相结合,比较了不同实验条件下DIC方法与应变片测量的结果,分析认为测量误差主要来源于摄像机噪声及离面位移.鉴于这两种误差难以消除,探索了一种误差修正方法,对系统误差进行修正并得到满意结果.
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