This study investigated the use of an eddy current technique for detecting side transverse cracks in a railhead. Quantitative analysis of defect signals in a railhead with side transverse cracks was realized through actual defect detection and finite-element simulation. In eddy current testing of the railhead, first, the general pattern of variation in the detected signals was obtained for different sizes of cracks via actual defect detection of rail samples. Then, finite-element simulation was used to verify the accuracy of the experimental results and to test the relationships between the detected signals and the size and depth of the cracks. The simulation results show that an extremely linear relation between crack depth and output signals in quantitative length of crack cases. In the results, simulation results can be applied to the analysis of the actual detected data. The eddy-current-defect detection method that combined experiment with simulation was very effective and can be applied in future research.
