Crack Parameter Determination Based on Multiple-Window Matching Strategy and Crack Grid Geometry Analysis

Accurate deformation measurement of building materials has consistently been a focal point of research within the field of material testing. This paper proposes a robust 3D crack parameter estimation approach to measure the crack propagation characteristics of concrete pillars under compression testing. Through the use of an improved multiple-window matching strategy and other advanced image processing algorithms, the precise positional information of speckle target points can be calculated in speckle image sequences. 3D point cloud data and full-field deformation of target points on the concrete pillar surface can be further calculated through photogrammetric analysis and spatiotemporal analysis, respectively. Finally, a robust crack estimation algorithm based on grid geometry analysis is proposed to extract accurate crack parameters in the presence of complex speckle texture interference. To verify the superiority and reliability of the proposed approach, both a simulation test and an empirical test were conducted. The experimental results, including positional comparisons with previous matching strategies and displacement comparisons with third-party equipment, corroborate the effectiveness of our method.