Mechanism of rail corrugation formation in straight track sections with Cologne-egg fasteners
Corrugation phenomenon with short-wavelength waves on the steel rail surface was identified in the straight track section of the domestic subway using the Cologne-egg fastener.The CAT corrugation instruments were employed to examine the static characteristics of rail corrugation,while the frequency response function of the track structure and modal characteristics of the wheelset were tested through a force hammer impact method.A wheel-rail coupled finite element model,accounting for unsprung mass,was established using ABAQUS software.Subsequently,a three-dimensional transient rolling finite element model was developed.The modal characteristics of the track and transient rolling features of the wheel-rail coupling under coupled conditions were analyzed.Employing track structure vibration theory and transient rolling theory,the dynamic characteristics of the wheel-rail coupled system and its correlation with rail corrugation were explored.Results indicate nearly identical wear degrees on the left and right track rails in the straight track section,with the main wavelength of rail corrugation being 30～40 mm.At a speed of 80 km/h,the corrugation wavelength's passing frequency ranges from 555 to 740 Hz.The modal vibration mode of the wheel-rail coupling system within this frequency range mainly exhibits the vertical bending vibration of the rail relative to the track slab.Under the excitation of 25～50 mm short-wavelength pits,the difference in vertical forces between the wheel and rail exhibits a significant frequency,aligning with the vertical bending vibration frequency of the wheel-rail coupling system at the corrugation wavelength's passing frequency.Rail corrugation generation is not significantly correlated with the vertical Pinned-Pinned frequency of the rail in this section but is primarily induced by surface damage exciting the high-frequency inherent characteristics of the rail within 570～710 Hz.Track structure corrugation generation is mainly linked to the high-frequency inherent characteristics of the track structure,with the excitation of high-frequency modal characteristics in the wheel-rail coupling being the fundamental cause for inducing and exacerbating rail corrugation development.The research results can provide a theoretical foundation for understanding the formation of rail corrugation in the straight track section of the Cologne-egg fastener.
Cologne-egg fastenersrail corrugationwheel-rail coupling dynamic characteristicspit excitationmid-high frequency modes
万方数据
维普
