| In recent years,due to the enhancement of wheel-rail interaction,the damage of vibration and noise to the environment has been aggravated to some extent.Among them,with the advancement of urbanization,the vibration and noise of urban rail transit have more severe negative effects on the surrounding rail trunk lines.Wheel-rail system noise plays a dominant role in the noise of rail transit.Therefore,the suppression and control of wheel-rail system noise has become the most important topic in the research of vibration and noise of rail transit.Many scholars have made effective prediction on the noise of rail and wheel respectively,carried out numerical simulation on the noise of wheel-rail system,and suppressed the predicted noise value.In order to study the sound radiation characteristic of the wheel and rail influence on wheel/rail system,this paper respectively established the finite element model of wheel and rail,the vibration response and sound radiation characteristics of the calculation and analysis,and based on the wheel/rail coupling dynamics,the wheel/rail coupling finite element model was established,the acoustic radiation characteristics of wheel and rail and wheel/rail coupling model were analyzed.The results of this paper can be used for reference in the future study of wheel-rail coupling acoustic radiation characteristics.(1)This paper establishes a single 915 MMS wheel finite element model.In this model,the constraints of wheel-to-wheel are simulated with fixed constraints,and the modal shapes and vibration response characteristics of the wheel are calculated and analyzed.In addition,the spherical PML(Perfect Matching Layer)is established and the radiated sound power of the wheel is calculated.In this paper,a damped wheel model is established according to the modal shapes of the wheel,and two groups of models are set up to compare the damped wheel with the damped wheel with the damped wheel with the local annular wheel.The effects of vibration and noise reduction are simulated and compared,and a more reasonable noise reduction scheme is proposed.(2)The finite element model of 60kg/m rail of ballastless track was established in this paper.For the under-rail part,this paper simplifies the spring damping element of the under-rail fastener and the track-plate system,and establishes the finite element model of the track-bed.Based on the finite element method,the modal shapes,harmonic response characteristics and acoustic radiation characteristics of the rail are calculated and studied.According to the acoustic vibration characteristics of the rail,two models of damped rail and dynamic vibration absorber rail are established in this paper,and the rationality of the two models is compared through calculation and simulation.(3)Based on the study of the acoustic vibration characteristics of the wheel and rail,the wheel-rail coupling finite element model was established,the wheel-rail equivalent force was calculated,and the acoustic radiation characteristics of the wheelrail coupling model were predicted.The prediction results show that coupling vibration occurs when the wheel and rail contact,and transverse coupling vibration occurs in the low frequency band of rail under vertical excitation.In the low frequency band,the sound radiation of wheel-rail coupling is mainly contributed by rail noise,while in the high frequency band,the noise of wheel-rail coupling is mainly contributed by wheel noise.(4)Based on the wheel-rail coupling radiated acoustic vibration characteristics,two noise reduction schemes,the damping wheel-rail coupling model and the wheelrail coupling model of dynamic vibration absorber,were established,and the radiated acoustic power of the two schemes was predicted.The prediction results show that the damping constraint has a good effect on the vibration and noise reduction of the wheelrail coupling vibration in the full frequency range.Rail dynamic vibration absorber plays an obvious role in reducing vibration and noise in a certain frequency band. |
PDF Full Text Request