Comparative Study of Digital Image Correlation Method and Sampling Moiré Method for In-plane Displacement Distribution Measurement

Abstract

Comparative Study of Digital Image Correlation Method and Sampling Moiré Method for In-plane Displacement Distribution Measurement Shien RI, Qinghua WANG, Shuichi ARIKAWA, Satoru YONEYAMA Displacement distribution gives useful information to understand the deformation behavior in materials science. Full-field optical methods, including the digital image correlation method and the sampling moiré method, are useful and effective to measure the displacement and strain distribution of materials by using a random pattern or a regular repeated pattern. In this study, we performed a comparative study to evaluate the measurement accuracy for digital image correlation and sampling moiré method using a same camera and an aluminum specimen subjected to same lighting condition. We discuss the advantage and disadvantage of both methods from the viewpoint of the accuracy under different signal-to-noise ratio (SNR) measurement conditions, and the analysis speed in case of single-core and multi-core CPU computing. Experimental results indicated that digital image correlation method is useful to measure the deformation under a high SNR condition in an easy way, and the sampling moiré method is robust to the measurement condition. Compared with the analysis speed, sampling moiré method is much faster than digital image correlation method. Furthermore, both methods are useful as a full-field measurement tool in experimental mechanics if a random pattern or arbitrary repeated pattern can be observed on the surface of materials.