Analysis Of Vibration Characteristics Of Wheelset Axle System Based On FEM

The increase in the load and the running speed of the train will increase the interaction between the wheel and the rail.The vibration and impact generated during the driving process will cause damage to the vehicle and the components of the track system.Therefore,it is necessary to analyze its vibration characteristics.This paper takes my country’s railway freight car wheelset system as the research object,establishes a dynamic model that considers the axle elasticity and wheel rotation state,and analyzes the vibration characteristics of the system under different excitations such as track irregularity and wheel polygon wear.The main contents of this paper are as follows:(1)Based on the structural and mechanical characteristics of the wheel-rotor system,a dynamic model of the wheel-rotor system considering the elasticity of the axle and the wheel rotation state is established based on the finite element method,and the inherent characteristics and critical speed of the system are solved by numerical calculation At the same time,it was compared with the results calculated by ANSYS to verify the accuracy of the modeling method proposed in this paper.(2)A wheel-rail contact space model considering the elastic deformation of the wheelset is established,and the wheel-rail contact parameters such as wheel-rail contact points are solved.The method of solving wheel-rail normal force and wheel-rail creep force/moment is introduced,and the load matrix of the system is obtained.Numerical simulation of the track spectrum is carried out,and the vibration characteristics of the system under different excitations,the elastic deformation of the axle and the characteristics of rotating travel are analyzed.(3)The formation mechanism and treatment measures of wheel polygon wear are introduced.Two wheel polygon excitation models of single harmonic and superimposed harmonic are established and compared.A single harmonic model is used to study the influence of various parameters of the wheel polygon on the vibration characteristics of the wheelset.The results show that the force between wheel and rail and system vibration acceleration will increase with the increase of vehicle speed,polygon order and amplitude.(4)The influence of wheel-set structure parameters such as tread shape,wheel diameter,and axle inner diameter on the vibration characteristics of the system is analyzed.The results show that changing the structural parameters of the wheelset has little effect on the vibration characteristics of the system,but the use of abrasion-shaped treads and increasing the wheel diameter can reduce the wheel-rail contact stress,which is beneficial to increase the vehicle load.Through the research in this paper,the dynamic modeling of the wheel-rotor system considering the elasticity of the axle is completed,and the vibration characteristics of the system under different excitations are obtained.The influence laws of vehicle running speed,wheel polygon wear order,amplitude,and wheelset structural parameters on vibration characteristics are clarified.It has certain theoretical guiding significance for the design of the wheel set system and the determination of the repair limit of the wheel polygon.