Short-pitch corrugation formation on resilient fastener metro tracks explained using rail-bending vibrations within the bogie wheelbase

Abstract

Short-pitch corrugation is a serious problem on resilient fastened railway track for many metro lines, causing severe noise and vibration that shortens the life of the vehicle and track components. To address this problem, the formation mechanism of this kind of corrugation is investigated in this study. The corrugation characteristics and natural frequency of the resilient fastener track are determined by field investigations. Then, ‘frequency sweeping’ and long-term rail-roughness prediction models are developed to reveal the crucial role of the interactions between two wheelsets in the corrugation formation and to estimate the effects of speed variations and bogie wheelbase on corrugation growth. The spectral analysis results indicate that the spatial frequency spectrum exhibits several peaks at equal intervals due to the short-pitch corrugation of a resilient fastener metro track, which are related to the third-order rail-bending vibration within the bogie wheelbase at about 775 Hz. In addition, large and small speed variations affect the wavelength and depth growth of the corrugation, respectively. The growth of corrugation depth is amplified when the resonance frequency associated with the corrugation formation is an integer-multiple of the wheel-passing frequency. The wheelbase is also an important factor in determining the corrugation wavelength because of its influence on the resonance frequency.

Formation Mechanism of Rail Corrugation for Modern Tram Lines

“…The occurrence of rail corrugation is closely related to the dynamics of vehicle-track system, therefore, for different vehicle operating environments, the occurrence probability and apparent characteristics of rail corrugation are not the same [1]. Rail corrugation is very easy to induce abnormal vibration and high-frequency noise in the wheel-rail system, damaging system components and adversely affecting the stability of vehicle operation [2,3]. At the present stage, the research on rail corrugation is mainly concentrated in the metro line, which is due to the metro system with many small radius curves, frequent starting and braking, the complexity of track structures and other objective factors [4][5][6], and the relevant results have certain positive significance for the understanding of the mechanism of metro corrugation and the control of the corrugation evolution [7,8].…”