Detection of closed cracks on the rail surface in thermography NDT

Eddy current thermography is an emerging detection approach in the field of nondestructive testing (NDT), offering a high resolution to surface defects. In recent years, this method has also been used for surface defect detection of wheel-rail. In this study, a moving mode of eddy current thermography is used for closed crack detection on the rail surface, and the temperature distribution corresponding to different crack depths is analyzed. Firstly, the simulation module is used to analyze the eddy current distribution around the defect. Then, the dynamic experiment was carried out, and the tensor decomposition is used to enhance the feature of infrared image. Finally, quantification analysis of defect characteristics is performed.