Origami structures and origami metamaterials have rapidly emerged as research frontiers and hotspots in fields such as materials science, smart structures, and robotics in recent years. Accurate measurement of the mechanical properties of origami structures is essential for their analysis, design, and application. Digital image correlation (DIC) technology is a non-contact optical measurement method that can be used for three-dimensional (3D) shape, deformation reconstruction and strain analysis. However, the depth discontinuities in origami structures cause discrepancies between two-dimensional (2D) image mapping and true 3D deformation, leading to accuracy decrement of image-based DIC for strain analysis on 3D geometric surfaces. This paper proposes a depth-guided strain analysis method to accurately achieve deformation and strain measurement on origami structures. By selecting the data points from a continuous and smooth subset under the guidance of depth map, the method can accurately compute strain distribution on 3D surfaces with complex geometric structures. Experiments on a Miura-ori structure validate the proposed method’s capability for accurate deformation and strain measurement on complex structures, providing a feasible experimental approach for analysis of 3D structural behavior of origami structures.

Rotor blades in aero-engines operating in sand-laden environments are highly susceptible to particle-induced erosion. Conventional sand ingestion experiments primarily rely on post-test disassembly, which lacks the capability for real-time surface shape analysis. To overcome this limitation, this study proposes a high-precision three-dimensional (3D) shape measurement method for ultrafast dynamic scenarios, based on pulsed laser illumination and stroboscopic structured light. In the proposed approach, a pulsed laser is employed to illuminate a physical grating, generating stroboscopic structured fringe patterns that are projected onto high-speed rotating blades. The deformed fringe images are synchronously captured by a high-speed camera and processed using Fourier transform profilometry (FTP) to reconstruct fine surface features with high accuracy. Compared with conventional LED-based stroboscopic systems, the pulsed-laser-based scheme effectively suppresses motion blur and significantly improves image intensity under ultra-short exposure conditions. Experimental results demonstrate that stable and high-quality fringe acquisition can be achieved at high rotational speeds. The method enables precise quantification of micro-scale defects, such as scratches and pits, providing a reliable solution for in situ monitoring and performance evaluation in aero-engine sand ingestion tests.