Abstract:Digital image correlation method currently suffers from inadequate systematic calibration methods and an incomplete metrological traceability system. To address these technical challenges, this study proposes a novel calibration method based on laser interferometry, integrated with a custom-designed optical system for local deformation measurement. Through finite element simulations, we systematically investigated the stress stiffening effect in strain plates under tensile loading. A coupled thermo-mechanical deformation model was developed via theoretical analysis and experimental validation, quantitatively characterizing the influence of convective heat transfer on the strain plate surface regarding measurement accuracy. Furthermore, the implementation of an Abbe error compensation mechanism effectively mitigated nonlinear errors induced by microscale bending deformations during tensile loading. Comprehensive uncertainty analysis was conducted to evaluate both the standard uncertainty components from various influencing factors and the overall measurement uncertainty of the calibration system. Experimental results demonstrate that the proposed laser-interferometry-based digital image correlation calibration device reduces measurement uncertainty in standard strain fields to 1.9%-0.83%. This study establishes a crucial reference for developing a traceable calibration framework for digital image correlation-based strain measurement systems.