Metrological performance quantification of a 3D-DIC system

Three-dimensional digital image correlation (3D-DIC) is widely used as a standard optical technique for shape and deformation measurement. In practice, the metrological performance of a 3D-DIC system must be fully understood and quantified to determine its measurement ranges and its measurement quality. In this work, by directly using the calibration and matching results of 3D-DIC calculation, easy-to-implement quantitative methods are proposed to evaluate key metrological parameters (i.e., common field of view (CFOV), magnification and displacement measurement uncertainty) for a 3D-DIC system. For validation, the CFOV of various 3D-DIC systems with different configurations was measured. Also, translation experiments were carried out and measured by these 3D-DIC systems. The experimental results demonstrated good agreement with theoretical predictions, validating the efficacy of the proposed methods. Finally, the proposed method was employed for characterizing the deflection of a cantilever beam measured by a specific 3D-DIC system. The methods presented in this work can be easily integrated into existing 3D-DIC software for better use of this powerful technique.