Single-camera displacement field correlation method for centrosymmetric 3D dynamic deformation measurement

Abstract

Three-dimensional (3D) deformation measurements are a key issue in experimental mechanics. In this paper, a displacement field correlation (DFC) method to measure centrosymmetric 3D dynamic deformation using a single camera is proposed for the first time. When 3D deformation information is collected by a camera at a tilted angle, the measured displacement fields are coupling fields of both the in-plane and out-of-plane displacements. The features of the coupling field are analysed in detail, and a decoupling algorithm based on DFC is proposed. The 3D deformation to be measured can be inverted and reconstructed using only one coupling field. The accuracy of this method was validated by a high-speed impact experiment that simulated an underwater explosion. The experimental results show that the approach proposed in this paper can be used in 3D deformation measurements with higher sensitivity and accuracy, and is especially suitable for high-speed centrosymmetric deformation. In addition, this method avoids the non-synchronisation problem associated with using a pair of high-speed cameras, as is common in 3D dynamic measurements.

Three-dimensional measurement of small-object surfaces on the basis of fiber optic interferometric fringe projection

“…cosðΔθÞ; (1) where I 1 and I 2 denote separate intensities in the field of the two light sources, and Δθ is the corresponding phase difference. In Eq.…”

“…A new optical information method developed using 3-D shape measurement technology exploits an optical image to detect and transmit information and extract relevant details from captured images, thus completing the recovery and measurement of the 3-D shapes of objects in a computer. [1][2][3] Therefore, phase measurement profilometry based on fringe-structured light projection satisfies the demand for 3-D object surface topography measurement in the previously mentioned application domains. This technology applies the principle of optical triangulation measurement, which can also be applied to the 3-D surface topography measurement of static and dynamic objects.…”