A New ACFM Probe for Inspection of Rail Crack at High Speed

The detection of rail crack is of great significance to ensure the safety of railway transportation. To improve the efficiency of railway operation, it is necessary to realize the high-speed detection. Based on the alternating current field measurement (ACFM) technology, this paper propose a C-shaped probe which is specially suitable for railway inspection. Using the finite element method, compared with the traditionnal U-shaped probe used in ACFM, it is verified that the C-shaped probe proposed induces a larger uniform current area on the rail, and the crack assessment is more accurate. An ACFM inspection system based on a C-shaped probe is established, and the high-speed railway turntable sample is inspected at a speed of 20km/h120km/h. The experimental results show that the established system can stably detect all surface cracks. It has the same detection ability and sensitivity at different speeds, and has good identification ability for different depth cracks.