Concrete Crack Detection through Full-Field Displacement and Curvature Measurements by Visual Mark Tracking: A Proof-of-Concept Study
In this study, a noncontact vision-based sensing method is proposed to measure surface displacements and curvatures and to detect cracks in a reinforced concrete slab. The proposed method includes five independent modules for structure boundary identification by a dynamic programming algorithm, boundary movement tracking by a contour tracking algorithm, distinguishable surface feature detection by speed-up-robust features, feature (visual mark) tracking by a three-stage data association algorithm, and displacement interpolation from those at visual marks by a Delaunay triangulation algorithm. The displacement field was used to evaluate the slab curvature that functioned as a crack indicator. The proposed data association algorithm for visual mark translation, linking, and connection was successfully applied for visual mark tracking of concrete slab images. The proposed algorithms used in five modules are computationally efficient, making them viable tools for real-time structural health monitoring. By persistently tracking the features and positions of spatially distributed visual marks in time-lapse videos, the displacement time histories at mark locations are successfully evaluated. The relative error of displacement measurements for the tested concrete slab is approximately 1.24%. The proposed method was applied to successfully detect cracks of a full-scale reinforced concrete slab from image analysis. Unlike contact measurements, the proposed noncontact measurement is not affected by concrete cracking.
Z. Yin et al., "Concrete Crack Detection through Full-Field Displacement and Curvature Measurements by Visual Mark Tracking: A Proof-of-Concept Study," Structural Health Monitoring, vol. 13, no. 2, pp. 205-218, SAGE Publications Ltd, Mar 2014.
The definitive version is available at http://dx.doi.org/10.1177/1475921713517289
Civil, Architectural and Environmental Engineering
Keywords and Phrases
Crack Detection; Data Association Algorithm; Displacement And Curvature; Feature Detection And Tracking; Noncontact Measurement; Visual Marks; Concrete Slabs; Crack Detection; Strain Measurement; Structural Health Monitoring; Surface Measurement
International Standard Serial Number (ISSN)
Article - Journal
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