High-speed stereo-digital image correlation using a single color high-speed camera.

Abstract

A simple and practical high-speed stereo-digital image correlation (stereo-DIC) technique using a single off-the-shelf high-speed color CMOS camera is described in this work. By using the high-speed color CMOS camera and suitable optical filters, the recorded color images can be directly separated into red and blue channel sub-images with negligible color cross-talk between sub-channel images, which offers evident efficiency and accuracy advantages over the existing technique we proposed recently [Opt. Lasers Eng.95, 17 (2017)OLENDN0143-816610.1016/j.optlaseng.2017.03.009]. These separated sub-channel images can then be processed by regular stereo-DIC to retrieve the desired kinematic fields on the test object surface. The accuracy and precision of the established high-speed stereo-DIC system were characterized by measuring the displacements of a stationary object, and the results show good agreement with theoretical predications. To show the broad utility and practicality of the proposed method, three typical experiments, involving (i) transient displacement and velocity measurement of a rotating fan; (ii) full-field vibration measurement of a rectangular aluminum panel; and (iii) transient 3D surface shape, displacement, and strain fields measurement of a balloon during the whole explosion procedure, were carried out. The results show that, by using a proper high-speed color camera, high-speed 3D shape, displacement and deformation measurements can be realized in a cost-effective and easy-to-implement manner. The proposed technique demonstrates great potential in impact engineering, explosion, and vibration tests.