Abstract:
The rapid development of high-speed railway in China has significantly improved travel, and thus, people's quality of life. Travel times have been greatly shortened and work efficiency has improved considerably. China's high-speed railway network is becoming a "great artery for the rapid development of national economy". However, the wheel diameter of the high-speed trains in operation continues to decrease due to abrasion and reprofiling. At various stages of diameter reduction, varying degrees of polygonal wear occur. At some stages, polygonal wear is severe and significantly increases the forces between the wheel and rail, resulting in strong vibration and noise in railway vehicles and tracks. This problem affects the quality of the train operation, passenger comfort, and the service life of the vehicle and track components. Serious so-called out-of-roundness wear can even threaten the operational safety of a train. In this paper, the types of out-of-roundness wear are introduced. They are mainly divided into two types:local out-of-roundness wear and out-of-roundness wear along with the entire rolling circle of the wheel. Local out-of-roundness wear includes wheel flats, spalling, shelling, squatting, and other local defects. Polygonal wear, which is commonly observed on the wheels of various recent high-speed trains, is another type of out-of-roundness wear. In the lifecycle of a wheel, its diameter decreases due to wear and reprofiling, and the order (or wavelength) and speed at which polygonal wear occur differ. In this paper, the state of the art of out-of-roundness wear in railway vehicle wheels is reviewed in detail, examining a total of 75 papers. The review analysis shows that research on noncircular wheel abrasion can generally be divided based on the following aspects. (1) The effect of out-of-roundness wear on the dynamic behaviour of the vehicle/track system and vehicle noise:these studies show that the amplitude and wavelength of polygonal wear, vehicle operation speed, and axle weight significantly influence the dynamic behaviour of the coupled vehicle/track system and vehicle noise. (2) The mechanism and development rules of out-of-roundness wear, and detection techniques:to date, there has been no consensus on the mechanisms of polygonal wear in wheels and its development, and further research is pending. However, the likely origin of polygonal wear is the high-frequency flexible resonance of the bogie system, which occurs under fierce excitation of wheel and rail irregularities. High-order polygonal wear develops quickly if the operation speed of the train, excited high-frequency flexible resonance frequency, and wheel circumference satisfy a specific condition. (3) Detection techniques for out-of-roundness wear. Finally, future research in the field is forecasted, including the development of a model of railway vehicle/track rigid-flexible coupling dynamics to reproduce the initiation and development of out-of-roundness wear and further clarify the mechanism of polygonal wear, measures for suppressing out-of-roundness wear through changing commercial operation condition, and building intelligent wheel-roundness modification devices to suppress and remove out-of-roundness wear on wheels.