Abstract
Continuously welded rail (CWR) has been widely applied in modern railway structures, and its performance is directly related to the safety of railway transportation. After the removal of the rail joints, the CWR cannot expand and contract freely. The longitudinal temperature stress within the CWR turns out to be the core structural parameter in the maintenance and repair of the track. In this study, an ultrasonic theoretical model of the rail temperature force was established, and the mechanism of the critical refracted longitudinal wave to detect the rail temperature stress was analyzed. A numerical simulation calculation was conducted with the three-dimensional finite element model, and the longitudinal wave incidence angle, frequency, and transducer spacing were calculated. The impact of critical factors on the accuracy of refracted longitudinal wave detection temperature stress was investigated. The ultrasonic acoustic propagation under the corresponding stress value of the rail was calibrated to eliminate the influence of residual stress and ensure the accuracy of ultrasonic detection of temperature stress. Finally, an online rail temperature stress monitoring system was built, and a long-term operation was carried out in the Changzhou section of the Shanghai-Nanjing high-speed rail. The monitoring data of the line in 2019 was obtained, and the temperature stress change of the line was recorded. The data showed that the ultrasonic sound obtained by real-time monitoring could accurately reflect the temperature and force changes of the rail. This proposed method is expected to provide a solution for online and remote acquisition of the temperature stress of the CWR. The accumulated long-term monitoring data is of great significance to the prevention plan for rail expansion and rail breakage.
Highlights
The continuous welded rail (CWR) has gained wide application throughout the world because it reduces the impact load between the wheels and the rails with no rail joints to effectively reduce train vibration, improve the train speed, and extend the service life of the rails and wheels.[1]
The results showed the strong sensitivity of critical refraction longitudinal waves to the residual stresses of the components
When the temperature stress is detected by the critical refraction P-wave, the transducer spacing should avoid the integral times of echo distance to improve the accuracy of critical refraction longitudinal wave
Summary
The continuous welded rail (CWR) has gained wide application throughout the world because it reduces the impact load between the wheels and the rails with no rail joints to effectively reduce train vibration, improve the train speed, and extend the service life of the rails and wheels.[1]. Keywords Temperature stress, critical refraction longitudinal wave, key influence factors, residual stress, monitoring system
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
