METHODS FOR DETERMINATION OF DEFORMATIONS WITH THE USE OF DIGITAL IMAGE CORRELATION TECHNOLOGIES

Abstract

In order to obtain reliable information about the stress-strain state of the structure, subjected to loading, it is necessary to determine deformations` distribution. In some cases, it is almost impossible to assess stress-strain state with the traditional approaches. However, the DIC methods provide reliable information about the fields of displacement and deformation almost without limitations. Such approaches are rather effective for determination of the stress-strain state on smooth surfaces and in zones with stress concentrators. The DIC method is based on the comparison of the intensity of speckle pictures` distribution of optically rough surfaces. The combination of the intensities of correlation peaks with the corresponding calculation algorithms at the subpixel level makes it possible to obtain high measurement accuracy with simpler hardware compared to electronic interferometry technologies. The main purpose of this work is the detailed analysis of techniques and methods for determination of deformations with the use of digital image correlation. The article includes detailed review of existing studies of this topic and description of main principles for analytical computation of the optical data.