Research on Quantity Traceability Method and Calibration Device of DIC Strain Field Measurement System Based on Laser Interference Principle

At present, there is a lack of systematic calibration methods and traceability systems for non-contact 3D strain measurement systems. Based on the principle of laser interference, a method for traceability of DIC values was studied, and a strain calibration device was designed to generate a uniform two-dimensional strain field using material axial tension. By analyzing and compensating for the Abbe error in the deformation measurement process, and evaluating the standard uncertainty introduced by various influencing variables during the measurement process, the strain measurement results and corresponding extended uncertainty are finally obtained. The measurement uncertainty of the strain calibration device is U=1.4<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">με</sup> ~2.1<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">με</sup> (measuring range: 94.2<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">με</sup> ~945.5<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">με</sup>, k=2).