An Accurate Method for Shape Retrieval and Displacement Measurement Using Bi-Prism-Based Single Lens 3D Digital Image Correlation

作者：Wu, L. F.; Zhu, J. G.^*; Xie, H. M.^*; Zhang, Q.

来源：Experimental Mechanics, 2016, 56(9): 1611-1624.

DOI：10.1007/s11340-016-0193-7

• Three dimensional digital image correlation (3D DIC)
• Single camera
• Entocetric lens
• Bi-prism
• Strain measurement

The bi-prism-based single lens 3D digital image correlation (BSL 3D DIC) technique is a 3D DIC method developed in recent years. The BSL 3D DIC is able to reconstruct the morphology of an object and track its 3D displacements using only a single camera, which significantly improves the integration level of the 3D DIC system and simplifies the system calibration process. In this paper, a novel and practical shape retrieval method is proposed to improve the measurement accuracy of the BSL 3D DIC technique and expand its applicability to strain measurement. The proposed method is based on a geometrical optics analysis using the reverse ray tracing method, which is performed in 3D space and takes into account the possible model errors induced by the system misalignment and the lens distortion. Experimental results demonstrate that the proposed method suffers from only a small error in morphology reconstruction (less than 0.3 %) and is able to measure the in-plane elastic strains with an accuracy of 95 mu I mu.

• 出版日期2016-11
• 单位清华大学; 江苏大学