Incremental calculation for large deformation measurement using reliability-guided digital image correlation
Incremental calculation for large deformation measurement using reliability-guided digital image correlation
复制标题
使用可靠性引导的数字图像相关性进行大变形测量的增量计算
DOI：
10.1016/j.optlaseng.2011.05.005
复制
发表时间：
2012-04-01
影响因子：
4.6
通讯作者：
Xia Yong
中科院分区：
文献类型：
--
作者：
Pan, Bing;Wu Dafang;Xia Yong
传统的数字图像相关（digital image correlation，DIC）技术使用固定的参考图像提供高精度的测量，但是当由于大的变形、严重的照明波动或其他原因而在变形图像中发生严重的去相关效应时通常失败。本文提出了一种增量式可靠性引导的数字图像相关（RG-DIC）技术，将新近发展的RG-DIC技术与参考图像自动更新方案相结合，用于大变形测量。增量式RG-DIC技术在原始参考图像中定义一个种子点，并在变形图像中搜索种子点，如果估计的相关系数大于预设阈值，说明变形图像中不存在严重的去相关效应，则利用RG-DIC技术继续进行相关分析，得到全场位移。否则，选择刚好在当前变形图像之前记录的图像作为更新的参考图像以进行相关性分析。然后，通过比较当前变形图像和更新的参考图像提取的增量位移可以被累积以确定总体变形。所提出的技术的有效性证明通过检索的全场变形的泡沫样品进行大的压缩变形。(C)2011爱思唯尔有限公司保留所有权利。
Conventional digital image correlation (DIC) technique using a fixed reference image provides high-accuracy measurements but normally fails when serious decorrelation effect occurs in the deformed images due to large deformation, serious illumination fluctuations or other reasons. In this paper, an incremental reliability-guided digital image correlation (RG-DIC) technique, by combining the recently developed RG-DIC technique and an automatic reference image updating scheme, is proposed for large deformation measurement. In the incremental RG-DIC technique, a seed point is defined in the original reference image and searched in the deformed images, if the estimated correlation coefficient is larger than a preset threshold, which means no serious decorrelation effect exists in the deformed image, the RG-DIC technique is used to continue correlation analysis to obtain full-field displacements. Otherwise, the image recorded just before the current deformed image is chosen as an updated reference image to proceed with correlation analysis. Afterwards, the incremental displacements extracted by comparing the current deformed image and the updated reference image can be cumulated to determine the overall deformation. The effectiveness of the proposed technique is demonstrated by retrieving the full-field deformation of a foam sample subjected to large compressive deformation. (C) 2011 Elsevier Ltd. All rights reserved.