Enhancing the Resolution Utilization for DIC Measurement of Slender Components Using Shear Imaging

Digital image correlation (DIC) is widely used for full-field deformation measurement, yet its spatial resolution is often underutilized when measuring slender components due to their high aspect ratio. To address this limitation, a novel virtual multi-camera DIC method that integrates a conventional dual-camera setup with two Michelson shear devices (MSDs) was proposed. Each MSD splits the image of the slender component along its longitudinal direction, projecting two segments side-by-side onto the same camera sensor. This configuration effectively enhances the resolution utilization of each camera, enabling high-resolution measurement of the entire slender surface without requiring additional cameras. The system is calibrated to establish extrinsic parameters between DIC subsystems, allowing stitching of 3D data from different regions. Experimental validation through translation and bending tests demonstrates that the proposed method achieves accurate full-field morphology and deformation measurements, with sub-pixel level agreement in overlapping regions. This approach offers a practical and cost-effective solution for enhancing DIC performance in constrained measurement environments.