Nondestructive analysis of rolling contact fatigue cracks using induced scanning thermography

Rolling contact fatigue (RCF) produced by wheel-rail interaction is now considered to be a critical factor that causes failure. Throughout this work, induced scanning thermography (IST) for detecting RCF defects at different depths is investigated. The original thermal sequences could not utilize the features at the heat dissipation stage; thus, a data reconstruction method, including principal component analysis (PCA) and 'flicker factorization, was employed to extract the spatial and time patterns. In addition, detectability was evaluated across a range of speed studies. The 'Ricker-PCA combination algorithms obtained defects with improved quality, showing a clear boundary over the velocity range of 1-4km/h, which dramatically suppressed background noise. A unique gradient response characteristic in the cooling phase was summarized and utilized through experimental verification in order to recognize defect width. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

This study investigates the use of induced scanning thermography (IST) for detecting rolling contact fatigue (RCF) defects at different depths. A data reconstruction method involving principal component analysis (PCA) and 'flicker factorization' is employed to extract spatial and time patterns. The detectability is evaluated across a range of speeds. The 'Ricker-PCA combination algorithms' achieve improved defect detection with a clear boundary over the velocity range of 1-4km/h, and a unique gradient response characteristic in the cooling phase is utilized to recognize defect width.