Railway wheel-flat detection and measurement by ultrasound

This work presents an innovative ultrasound technique designed to detect and quantify flats formed in the rolling surface of railway wheels. Differently from other approaches, ultrasonic pulses (Rayleigh waves) are sent over a measuring rail. The variations in the round-trip time of flight (RTOF) of the ultrasound pulse to the rail-wheel contact point allow detecting and quantifying the wheel-flats. In spite of the wear state of the irregularity, the method provides the loss of material and the length of the flat originally formed by abrasion. A theoretical background supports the technique which offers many advantages for railway maintenance. Simulations and experimental results match the expected ones.

► The research develops an innovative ultrasonic technique that allows sizing wheel-flats in railway wheel treads.
► The movement of the train over the rail is exploited to detect irregularities.
► Wheel-flats are measured with high-resolution.
► The technique is independent from the wear level of wheels and flats and it has a high noise rejection.
► No moving parts are required.