Research on axle press-fit defects detection optimizing

The wheel-set maintenance mainly depends on ultrasonic nondestructive testing techniques to detect defects. Wheels are pressed or shrunk on the axle, and the press-fit has significant influence on ultrasonic detection at press-fit part of the in service axle comparing with bare axle. Limited by the complex testing conditions of the press-fit interface, higher amplitude noise is present in the echo signal. In this paper, simulation and axle detection experiments and filtering algorithms optimization are used to improve the signal-noise ratio. The phased array ultrasonic probe parameters and arrangements are optimized by software simulation and reference axle testing. A series of defect detection experiments between bare axle and axle with press-fit have been complemented by using phased array ultrasonic. Ultrasonic signal processing and denoising algorithm has been conducted to effectively improve the signal-noise ratio.