Research on Lateral Stability of Vehicles with Lower Bolster Bogies

The linear and non-linear stability ana-lysis is made for vehicles with bogies of lower bolster structure,and the conclusion is obtained as follows:The modal conditions of instability of vehicles is the hunting modal conditions of bogies where the frame and wheelset have the vibration of the same frequency and phase,along with the wear of the wheel tread,the lateral stability of vehicles will decrease;When the primary horizontal stiffness decreases,the natural damping of hunting modal conditions of wheelsets will decrease.When the longitudinal stiffness of the traction rod decreases,the natural damping of the lateral vibration modal conditions of the frames will decrease and the lateral stability will decrease.The horizontal positioning stiffness of wheelsets and the friction factor of side bearings as well as the longitudinal stiffness of the traction rod have obvious effect on the lateral stability of vehicles with lower bolster structure,and change of any of the three parameters will affect the lateral stability of the whole car.