Dynamic characteristics analysis of rack railway track system under traction conditions by experimental test

Abstract The dynamic characteristics of the track system can directly affect its service performance and failure process. To explore the load characteristics and dynamic response of the track system under the dynamic loads from the rack vehicle in traction conditions, a systematic test of the track subsystem was carried out on a large-slope test line. In the test, the bending stress of the rack teeth, the wheel–rail forces, and the acceleration of crucial components in the track system were measured. Subsequently, a detailed analysis was conducted on the tested signals of the rack railway track system in the time domain and the time–frequency domains. The test results indicate that the traction force significantly affects the rack tooth bending stress and the wheel–rail forces. The vibrations of the track system under the traction conditions are mainly caused by the impacts generated from the gear–rack engagement, which are then transferred to the sleepers, the rails, and the ballast beds. Furthermore, both the maximum stress on the racks and the wheel–rail forces measured on the rails remain below their allowable values. This experimental study evaluates the load characteristics and reveals the vibration characteristics of the rack railway track system under the vehicle’s ultimate load, which is very important for the load-strengthening design of the key components such as racks and the vibration and noise reduction of the track system.