Analysis of Rotation Resistance of Bogie and Running Safety of Railway Vehicle

The vehicle system dynamics model of a specific metro vehicle was built up based on multibody dynamic theory. The relationship between the rotation resistance of a bogie and the suspension parameters was studied using the mentioned model. Besides, the influence of the rotational resistance of a bogie on the vehicle running safety was analyzed. The rotation resistance factor of the bogie was tested in a lab with uninflated air springs, inflated air springs, and overinflated air springs at various bogie rotation speeds to verify the simulation model. The results show that the laboratory test verifies the validity of the dynamic model. It also shows that the rotation resistance factor of the bogie goes up when the bogie rotates faster relative to the car body, especially with uninflated air springs. The bogie rotation resistance is mainly provided from the horizontal stiffness of the air spring, which changes little with the other suspension parameters. The bogie rotation factor can significantly affect the running safety of a vehicle on a slight curve track. The safety index gets worse when the vehicle runs faster in such conditions. Thus, to ensure vehicle safety, the bogie rotation resistance should be considered seriously.