Digital image correlation analysis for displacement measurements in cantilever beams

Abstract

Digital Image Correlation (DIC) uses digital images processing techniques, which allows the acquisition of displacement fields of an object in regions of interest. The difference between DIC and other conventional measurement techniques is that DIC allows measurement of noninvasive mode, resulting in a low cost benefit. DIC is a technique applied in civil engineering, mechanical engineering, materials science and biomedical engineering, among others. Thus, it can also be adapted and used in many different measurement conditions, allowing a quick and accurate processing of a large number of images. This work is aimed to measure displacements in a cantilever beam by using DIC technique. To this end, different configurations of markings in ASTM A36 steel beams were analyzed, which obtained displacement fields along the beams. Commercial software for images processing, based on DIC technique was used. The procedure was applied to loads of 0.05 N, 0.1 N, 0.2 N, 0.5 N, 10 N, 20 N and 50 N. Satisfactory results were found when compared to analytical values and the Finite Elements Method. Results for loads of 10 N presented a difference around 0.3 mm between analytical results and DIC. This demonstrated the potential of DIC for displacement measurements in cantilever beams.