Initiation Cause of Subway Rail Corrugation on Track with Rubber-Booted Short Sleepers

To investigate initiation cause of short-pitch rail corrugations occurred on curved tracks with rubber-booted short sleepers, field measurement and numerical simulation methods were employed. Firstly, establishment of the relationship for wavelength of the rail corrugation and dynamic behaviour of the track was facilitated by the field measurement. Then, wheel-rail contact parameters were calculated by a vehicle-track coupled dynamics model. Receptance of the tracks was measured by an impact excitation technique. At last, a linear model for the rail corrugation was established to analyze characteristic of rail wear based on the wheel-rail contact parameters and the receptance of the tracks. Rail wear rate of the tracks in the frequency domain was calculated during a vehicle running at curves. The initiation cause for rail corrugations with specific wavelengths occurred on the tracks with rubber-booted short sleepers was clarified. The results show that corrugations for the tracks with rubber-booted short sleepers have occurred at curves with radius of less than or equal to 800 m. Main wavelength of the corrugations is about 50−160 mm and level of the corrugations on low rails is higher than that on high rails. Passing frequency of the corrugations is in the range of 140−280 Hz, which is close to resonant frequencies (160−300 Hz) of the track with rail vibrating related to sleepers. Modal shape of the tracks exhibits rails and sleepers vertical vibrating on the slab in same and opposite directions at frequencies of 160−210, 250−300 Hz. Initiation of corrugation on the curved tracks is determined by the dynamic behavior of the tracks. Characteristic of corrugations exhibits the fixed-frequency mechanism, which means wavelength of the corrugations is related to the speed of vehicle.