Numerical and experimental study on adaptive stiffness yaw damper for suppressing abnormal vibration of high-speed trains

The mismatch between the parameters of the yaw damper and the equivalent conicity of wheel rail contact can lead to abnormal vibration of rail vehicles, while the stiffness variation range of traditional yaw dampers is very small, covering a limited range of equivalent conicity of wheel rail contact, resulting in the risk of carbody hunting at low conicity and bogie hunting at high conicity. To overcome the abovementioned shortcomings of traditional yaw dampers and reduce the abnormal vibration of high-speed trains under various operating conditions, this study proposes an adaptive stiffness yaw damper. The effectiveness of this solution was confirmed through roller testing rig and multi-body dynamic simulations. The results show that the device can dynamically adjust the stiffness according to the operating conditions of the vehicle, effectively reducing the carbody and bogie hunting under extreme wheel rail contact conditions, and thereby reducing the abnormal vibration of high-speed trains. At the same time, this device helps reconcile the trade-off between the curve negotiation performance and stability of vehicle, indirectly lessening the requirement for wheel–rail maintenance and reducing operational and maintenance expenses.