A Study On Digital Image Correlation Method (DICM) And Its Application

Digital image correlation (DIC) method is the production of combination of modern digital image processing technology and photomechanics. It has been come to front in the field photomechanics for these years. On basis of domestic and foreign research results , the novel DIC algorithms has been developed to improve precision and speed of calculation and to apply to deformation measurement of coating material and research of mechanics behavior of rare-earth ceramic material . In this paper, some improvements and innovations have been performed base on the traditional theory about DIC . Two-rank Tailor multinomial has been introduced to decrease cutting errors in subset displacement mode; B-spline interpolation is adopted to rebuild the subpixels in order to get the high precision ; BFGS method is applied to correlation iterative to reduce parameters and increase calculation speed moreever,to extend rank of subset displacement mode and increase precision. The corresponding computer software is developed which has fine pretreatment, high precision and speed. All measuring errors of DIC method and their origin are analyzed from two aspects of theory and experiment. Some corresponding measurement to eliminate these errors are proposed . The computer simulative scheme and a typical experiment are employed to test the reliability of the software . Results show that the method is stable and credible . The above method was successfully applied to the deformation measurement of coating material and research of mechanics behavior of rare-earth ceramic material . The results show that the method is feasible to aspects above mentioned , which also promotes a new effective method in the field of deformation measure and research of mechanics behavior .