Nonlinear Secondary Suspension Systyem Design And The Dynamics Simulation Of High-speed Freight Train Bogie

With the continuous improvement of the running speed of railway wagons,it is difficult for vehicles to maintain good dynamic characteristics in complex vibration environments,and higher requirements are imposed on the running stability of vehicles.Although the reduction of the vertical stiffness of the secondary suspension can reduce the vibration transmitted by the bogie to the vehicle body and improve the vertical stability of the railway wagon,it is difficult to meet the requirements of the railway wagon for the high load capacity of the second suspension.Therefore,it is more difficult to improve the vertical stability of railway wagon.In order to ensure the high-speed freight train bogie has excellent vertical running stability,improve vehicle dynamic performance.The vertical two-degree-of-freedom linear vibration model of the vehicle is established based on the structural characteristics of the rail vehicle in this paper,the influence of the vertical stiffness parameters and damping parameters of the first and second suspension on the system transmission rate is discussed,and to clarify the impact of rail vehicle suspension parameters on vehicle running stability.According to the negative stiffness characteristic of geometric nonlinear structures,the positive and negative stiffness parallel combination is adopted,and the nonlinear secondary suspension system is constructed by adding structural elements with vertical negative stiffness characteristics to the original secondary suspension system.The vertical single degree of freedom modeling of the the nonlinear secondary suspension system is established,and harmonic balance dynamics analysis is used to verify that the positive and negative stiffness parallel combination can reduce the system stiffness and improve its vibration isolation effect.On this basis,the vehicle's two-degree-of-freedom nonlinear vibration model is established,the influence of nonlinear secondary suspension parameters on the system transmission rate is discussed,and to clarify the impact of the influence of nonlinear binary suspension parameters on vehicle stability.The evaluation system of vehicle dynamic performance is established according to the corresponding specifications,and the dynamic simul ation analysis software is used to establish the vehicle model and analyze the dynamics.The vertical vibration characteristics of the main structure of the original vehicle model are analyzed and compared with the theory.At the same time,considering the limitation of the vertical maximum compression capacity of the secondary suspension,and the parameters of the secondary suspension are optimized to realize the integrated design of the secondary suspension bearing vibration isolation and limiting relative displacement,and make its various dynamic indicators meet the requirements of the specification.Compared with the original vehicle dynamics performance,the results show that the nonlinear secondary suspension system with parallel combination of positive and negative stiffness elements can realize high static bearing capacity and low dynamic stiffness characteristics through the internal parameter design of the suspension system.It greatly improves the vertical stability of the vehicle operation,and have a certain improvement on the curve passability,and the hunting stability in straight lines is basically the same as that of the original vehicle.