光学仪器, 2012, 34 (3): 5, 网络出版: 2012-12-06
二维数字图像相关方法的拉伸实验误差分析
An investigation of the experimental error of 2-D DIC method applied to tensile strain measurement
数字图像相关(DIC) 误差分析 刚体运动 离面位移 digital image correlation(DIC) error analysis rigid-body motion out-of-plane displacement
摘要
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。
Abstract
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.
王楠, 李恩普, 汤忠斌, 李发东. 二维数字图像相关方法的拉伸实验误差分析[J]. 光学仪器, 2012, 34(3): 5. WANG Nan, LI Enpu, TANG Zhongbin, LI Fadong. An investigation of the experimental error of 2-D DIC method applied to tensile strain measurement[J]. Optical Instruments, 2012, 34(3): 5.