Research on eddy current pulsed thermography for rolling contact fatigue crack detection and quantification in wheel tread

The in-seivice wheel-set quality is one of critical challenges for railway safety, especially for the high-speed train and heavy haul train. The shelling in wheel tread, initiated by rolling contact fatigue (RCF) damage, is one of the most significant phenomena and has serious influence on rail industry. The Ultrasonic testing technique is successful NDT method for inner defects in wheel-set and difficult to find the defect in surface area. Electromagnetic NDT methods have high sensitive on the surface crack but difficult to sub-surface crack in wheel tread. This paper studied the mechanicals of eddy current pulsed thermography for detection those defects. Some features of defects on wheel tread were abstracted and studied; one new inductive coil was designed for one experimental platform to test the rolling contact fatigue crack in real wheel tread. Based on the simulation results, the eddy current pulsed combined eddy current and thermography methods, can realize the detection.