Simultaneous measurement of three-dimensional deformation based on digital speckle pattern interferometry technology

Abstract

In the present study, a brief, efficient and synchronous 3D (three-dimensional) deformation measurement method based on digital speckle pattern interferometry (DSPI) and digital shear speckle interference (DSSPI) was proposed. Comparing with traditional multi-laser and multi-CCD DSPI methods, this method used a single CCD and two lasers to capture the speckle patterns from three sensitive directions simultaneously, which simplified the optical arrangement, reduced the system cost, and improved the detection efficiency effectively. Based on the proposed method, the phase maps could be obtained by space carrier method, and the phase maps included both out-of-plane deformation and in-plane strain information (vertical in-plane, horizontal in-plane and out-of-plane). According to the deformation and strain information, the 3D deformation distribution could be obtained through an integral operation. In the present study, the measuring algorithm and optical arrangement were described in detail, and experiments were carried out to verify the validity.