Strain Measurement Using Digital Image Correlation Method

• Main Authors: Yu-Hsiang Chen, 陳鈺翔
• Other Authors: Ji-Chun Lee
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/10901417533429290795

碩士 === 國立中興大學 === 機械工程學系所 === 99 === Digital image correlation method is a non-contact, non-destructive optical measuring method, the principle is the second image by comparing each pixel with the first image (reference image) in the fixed point of reference pixel correlation to find images from the second image with the first reference pixel has a maximum correlation of the pixels, the point that this reference in the second pixel of the image of the corresponding points in the statistics there are several kinds of method used to calculate the correlation coefficient, used in digital image correlation method is the most common use of Pearson''s correlation coefficient for correlation matching of operations. In this study, obtained by deformation of the surface before and after images, and image distortion as a reference image before using the digital image correlation method to find the reference image of each pixel in the deformed image of the integer corresponding to the point, and by a simple displacement equation and the brightness of the transformation model with the theory of the Newton equation of motion optimization, and then obtained through iteration after the surface displacement and strain in the deformation of sub-pixel part, and then calculate the displacement and strain by filtering the of smoothing, and then obtain the deformed surface in the global displacement field and strain field.