A Quantitative Detection Method for Surface Cracks on Slab Track Based on Infrared Thermography

Surface cracks are typical defects in high-speed rail (HSR) slab tracks, which can cause structural deterioration and reduce the service reliability of track system. However, question how to effectively detect quantify surface remains unsolved at present. In this paper, a novel crack-detection method based on infrared thermography is adopted rail-track slabs. method, thermogram acquired by an camera first processed with non-subsampled contourlet transform (NSCT)-based image-enhancement algorithm, crack located via edge-detection algorithm. Next, quantitatively crack, pixel-locating proposed, whereby width, length, area be obtained. Lastly, detection accuracy proposed different temperatures verified against laboratory test, scale model poured temperature-controlled cabinet used control temperature-change process. The results show that enhance edge details image extracted; quantification width reach 99%, whilst length 85%, essentially meets requirements HSR-slab-track inspection. This research could open possibility application IRT-based inspection HSR operations efficiency defect detection.