On-track Experiments on the Ride Comforts of an Articulated Railway Vehicle

An articulated railway vehicle (ARV) experienced an abnormal vibration on car body which deteriorates its riding comfort significantly. On-track experiments were conducted considering the wheel-rail interaction, the vibration transmission of primary and secondary suspensions, to locate the vibration sources and find a solution. Compared to the existing dynamics tests performed on a railway vehicle, the modes of car body motions were further recorded as well as its structural modes when the vehicle was operated on track. Furtherly, the lateral motion of the wheelset and car body were recorded by a video surveillance on-board to check the modes of motion of the vehicle system for the first time. The tests performed in this work extends the field measurement techniques and can be used on track for the railway vehicle dynamics analysis. It is shown that measured wheel profiles have a small radius difference which lead to a low equivalent conicity of wheelset, which in turn introduces a low-frequency hunting motion of wheelset in case of a soft steering. The yaw motion of the car body was excited by the wheelset hunting and then the coupled vibration between the wheelset and car body deteriorates the ride comforts of ARV. A solution of this low frequency vibration on vehicle system is to increase the wheelset conicity and has been verified on-track. Additionally, reduce the stiffness of the anti-yaw damper can improve the ride comfort in case of a low conicity.