Ultrasonic guided wave detection of point rail damage of high-speed railway turnout

The precise and efficient identification of damage in point rails of turnouts represents a critical and challenging technological issue that requires immediate attention. Guided wave inspection, as a non-destructive testing method, holds significant potential for practical applications in the research field focused on the identification of damage in point rails of high-speed railway turnouts. This study integrates rigorous theoretical analysis, advanced numerical simulation techniques, and meticulous experimental investigations to comprehensively investigate the excitation, propagation, and reception processes of ultrasonic-guided waves within the point rail. By strategically applying excitation signals at optimized positions specifically tailored for point rail detection, employing a frequency of 30 kHz, appropriate excitation modes are carefully selected. Defect identification within the extended point rail is performed from a dual perspective, encompassing both cross-correlation analysis and time-frequency analysis. The obtained results substantiate that when employing the cross-correlation coefficient to detect cracks in the elongated point rail, the sensitivity of crack detection is significantly higher in the rail bottom region as opposed to the rail head region. Furthermore, through the analysis of variations in the cross-correlation coefficient and the application of wavelet transformations to the guided wave signals, it is not only feasible to ascertain the presence and location of damages within the rail base region of the extended point rail but also to evaluate the relative size of the cracks. The findings of this research contribute a robust theoretical foundation for the subsequent analysis and evaluation of damage detection in high-speed turnout point rails.