Non-destructive residual stress measurement using digital image correlation method

In this paper, we examine the method of Digital Image Correlation (DIC) and introduce a new theory for measuring residual stresses in non-destructive mechanical parts. In this regard, with the aim of scientific proof, the new theory introduced into the review of the article related to the idea presented in this study and its details have been discussed. First, the principles of the method of digital image correlation and methods for calculating correlation coefficients are presented. With the aim of evaluating the authenticity of the outputs of digital imaging, by constructing the required equipment and performing empirical tests to perform the process, comparing the output results of the digital imaging overlap method and the finite element simulation results. In the following, the proposed theory is presented to measure residual stresses in mechanical parts by applying loads in the elastic and non-destructive regions. The proposed relationship, which is based on Hooke's law, is capable of evaluating and calculating residual stresses in a non-destructive, full-screen, and high-precision manner. Finally, In order to prove the theoretical theory, steel samples have been welded by the SMAW process and the amount of residual stresses in the compartments has been calculated.