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Rail corrugation is a phenomenon of great diversity but appears now to be substantially understood. This review proposes some differences in classification of the phenomenon to take account of work undertaken since a widely cited review was published by Grassie and Kalousek in 1993, it attempts to fill holes in an overall understanding of the problem, and answers questions that remained open in 1993 and several that have arisen since. All types of corrugation that have been documented to date are essentially constant-frequency phenomena. By treating the vehicle—track system in its entirety, treatments are proposed that impinge upon track and vehicle design as well as upon the wheel—rail interface where corrugation appears. There is no neat solution to rail corrugation, but it can be treated comprehensively and in many cases also prevented by using products that are already commercially available. Since the frequency of common wavelength-fixing mechanisms varies roughly in the range 50—1200 Hz, trains travelling at different speeds can produce corrugation of substantially similar wavelength by different mechanisms in different locations. Although historical data can no longer be checked, this is the most likely explanation of the belief that rail corrugation was a substantially constant-wavelength phenomenon.

Vertical bending vibration modes and rail wave propagation, including the damping characteristics, are the factors that cause rail corrugation. However, the ability to identify actual railways has been limited because of the huge number of sensors required for field tests. In this study, a novel and field-applicable method for identifying rail vibration modes and wave propagation characteristics is developed by multipoint hammering and the reciprocity theorem instead of multipoint measuring. Additionally, the proposed method is applied to an actual rail with a direct fastening track system on a bridge that has corrugation with a wavelength of approximately 0.04 m. As a result, the wavelength (wavenumber)-, group velocity-, and distance damping (attenuation) frequency relationship of the wave propagation is clarified in addition to the rail frequencies and mode shapes up to approximately 1500 Hz, including the pinned-pinned mode. Finally, the identified wavelength-frequency relationships and the measured rail irregularity can empirically demonstrate that the generated corrugation on the rail is produced by wave interference on the two axles in the bogie.

In this paper, an intelligent method to diagnose rail corrugation based on signal decomposition and entropy theory is proposed. The axle box acceleration signals are first decomposed into several components with different frequency bands by ACMP, EEMD and MODWT. By comparison, ACMP is able to successfully extract rail corrugation component from original signal without mode mixing. Energy entropy is then introduced here to quantify the degree of the rate of energy concentration. The analysis results show that the energy will change when rail corrugation occurs and the entropy will become small. It has been also proved that the entropy difference of rail corrugation and normal signal based on ACMP is the most significant. In addition, to intelligently diagnose rail corrugation, we combine energy entropy with energy index and the first mode energy, regarded as the input feature vector of LSSVM, to distinguish rail corrugation from mass data sets. It is obvious that the accuracy of ACMP-based technique is the highest.

Rail corrugation is a serious problem in a railway transportation system, aggravating the operational risk and shortening the lifetime of train–track system. In order to ensure the safety and reliability of the railway system, the detection of rail corrugation is very important. Thus, this study systematically summarizes the recent research progress of rail corrugation. First, this study introduces the definition of rail corrugation and the classification criteria. Then, the formation mechanism of rail corrugation is analyzed in detail, and its adverse consequences are investigated. Further, this study summarizes several main detection methods, which are corrugation-detection methods based on acceleration measurements, wavelet transform methods for corrugation evaluation, computer-vision-based methods for corrugation automatic detection, digital filtering algorithms for rail corrugation detection, and others. In this study, the formation mechanism and detection methods of rail corrugation are systematically described, and various corrugation-detection methods are also introduced in detail. This study not only provides a scientific basis for railway maintenance, but also lays a solid foundation for future experimental design and data analysis. This study can also guide engineering practice to improve the reliability and safety of railway systems. It also provides useful experience for future railway-engineering design and planning, as well as safer and more reliable operation. In general, this study can provide technical support for the detection of rail corrugation to ensure the safety of the rail–track system.

With a speedy advancement in vehicle speed and transport capability, a huge challenge has been imposed to improve railway vehicle dynamic behaviour and track design to ensure the optimum performance of railway vehicles and tracks. To safely negotiate the vehicle speed on circular and transition curve tracks several aspects such as wheel-rail wear, smooth ride and vehicle stability need to be analysed. The investigators have paid great attention to exploring the compatibility among vehicle stability and curving ability, parametric analysis and optimization of curving performance, minimising the wheel-rail wear and curve squeal noise etc. The present paper focuses on reviewing these past efforts made by the researchers.

This paper presents a deep learning approach for predicting rail corrugation based on on-board rolling-stock vertical acceleration and forward velocity measurements using One-Dimensional Convolutional Neural Networks (CNN-1D). The model’s performance is examined in a 1:10 scale railway system at two different forward velocities. During both the training and test stages, the CNN-1D produced results with mean absolute percentage errors of less than 5% for both forward velocities, confirming its ability to reproduce the corrugation profile based on real-time acceleration and forward velocity measurements. Moreover, by using a Gradient-weighted Class Activation Mapping (Grad-CAM) technique, it is shown that the CNN-1D can distinguish various regions, including the transition from damaged to undamaged regions and one-sided or two-sided corrugated regions, while predicting corrugation. In summary, the results of this study reveal the potential of data-driven techniques such as CNN-1D in predicting rails’ corrugation using online data from the dynamics of the rolling-stock, which can lead to more reliable and efficient maintenance and repair of railways.

In Chinese metro lines, Vanguard fastener system is widely used as vibration damping fastener. However, the rails mounted with this fastener system are deeply affected by rail corrugation. The generation mechanism of corrugation wear at a metro track mounted with Vanguard fastening is revealed through the numerical simulation method. A finite element model including two rails, the track system, and a leading wheelset is set up. The parameter sensitivity analysis is conducted to identify the dominant factors affecting the rail corrugation. Then, the remedy method to suppress the corrugation wear is put forward on the basis of the parameter analysis results. The results indicate that the severe corrugation wear on the inner rail is attributed to the self-sustained vibration of the wheelset–track system aroused by the saturated wheel–rail creep force. The frequency of the rail corrugation calculated by the model is very close to the measured data. The elastic modulus and the damping coefficient of the rubber rest pad in the Vanguard fasteners have a high impact on rail corrugation. Increasing the elastic modulus and the damping coefficient can effectively restrain or even eliminate the rail corrugation. Bringing the damping coefficient of the rubber rest pad above 0.0001 can significantly alleviate the rail corrugation. The influence of the damping and stiffness of the rubber pad under the floating slab track bed is negligible.

By establishing vehicle-track space coupled model and rail corrugation evaluation model, the generation mechanism of rail corrugation was analyzed in frequency domain and time domain, and development characteristics of corrugation were studied by using corrugation growth rate. Analysis based on frequency domain: through modal analysis and frequency response analysis on the finite element model of track structure, it is found that there are natural frequencies of track structure close to measured corrugation passing frequencies. It shows that the vibration modes corresponding to these frequencies can be more easily excited, which can cause the resonance phenomenon of track structure and form the rail corrugation at corresponding frequencies. Analysis based on time domain: the time-history curves of rail vertical vibration acceleration and rail vertical displacement are calculated by using vehicle-track coupled model and the frequency domain transformation of the time-history data is carried out. It is found that there are characteristic frequencies close to the measured corrugation passing frequencies, which indicates that the vibration of track structure at corresponding frequencies is an important reason to promote the formation of corrugation. The change of vehicle speed has no effect on characteristic frequencies of corrugation growth rate curves, which reflects the fixed frequency characteristic of corrugation. With the increase of train operation times, the corrugation corresponding to characteristic frequencies will gradually form and develop, and the increase of vehicle speed will increase the wavelength range and development speed of rail corrugation.

Rail corrugation poses a significant threat to train running safety in the field of railway engineering. Therefore, this study employs numerical analysis to investigate the evolution and formation mechanism of rail corrugation in high-speed railways (HSR). Firstly, a three-dimensional (3D) vehicle-track coupled dynamics (VTCD) model is established, which considers the longitudinal wheel-rail (WR) coupling relationship more adequately. Then, by integrating the USFD wear model into this 3D VTCD model, a long-term iterative wear model is developed to reproduce the corrugation evolution process. The predicted corrugation exhibits two distinct wavelength components and closely matches the sample obtained from China’s HSR, validating the established model in terms of reliability. Furthermore, the formation mechanism of these two wavelength components is investigated by analyzing the harmonic behavior of vehicle-track coupled systems (VTCS) and the evolution law of rail corrugation under different calculation conditions. The findings reveal that the 3rd-order vertical rail local bending mode (RLBM) between two wheelsets of a bogie (TW-B) is the primary factor contributing to the formation of the long-wavelength component of rail corrugation. The discrete supports of the fasteners do not affect the 3rd-order vertical RLBM, which can be stably excited. Moreover, the vertical rail vibration has a substantial coupled effect on the longitudinal WR creep. When the 3rd-order vertical RLBM is excited, the coupled effect and the negative longitudinal WR creepage together evidently promote the formation of the short-wavelength component of rail corrugation.

The objective of the current study is to investigate the formation mechanism of rail corrugation. According to the actual wheel-rail motion relationship, that is, considering the influence of the angle of attack (AoA), a single degree of freedom friction pair model considering different friction attributes was established. The system stick-slip oscillation characteristics under different friction attributes were analyzed by using the model, so as to explore the generation reason of corrugation. Meantime, combined with the parameter analysis of the power system, the corresponding control measures for the stick-slip oscillation were put forward to slow down the formation and development of corrugation. The results show that the lateral and vertical dynamics play important role on its stick-slip oscillation characteristics. The corrugation formation on the metro small radius curve is related to the unstable stick-slip oscillation induced by the negative slope friction creep property of wheel-rail interface. The parameter analysis illustrates that the unstable stick-slip oscillation can be effectively controlled by increasing the damping coefficient, increasing the modal stiffness, appropriately reducing the static vertical force of the contact interface and increasing the lateral velocity (AoA) within a certain range. Practically, knowing the formation mechanism of rail corrugation is conducive to understanding the evolution process of rail corrugation; meantime, by referring to the results of parameter analysis, the active control of stick-slip oscillations can be realized, thereby controlling the growth of rail corrugation.