Study On Vibration And Acoustic Radiation Characteristics Of Rail

With the rapid development of China’s railway track，it becomes a prominent issue whilevarious kinds of noise pollution generated by the interactions of wheel-rail when trainsoperate in a high speed. The vibration noise of the wheel-rail is the most prominent oneamong various noises produced by the train. The work of this paper is based on the study ofrail vibration and use boundary element method to make simulated analysis about the railradiated noise.The main content is as follows:1. Based on the ballastless track structure dynamics theory, The ballastless track as theobject of study, apply the FEM to built a three-dimensional finite element model of rail inANSYS and then get the admittance characteristic to confirm the validity of rail model by theharmonic response analysis.2. Loading wheel-rail force on the rail of track mode and get the vibration response ofrail by making transient dynamic analysis. Find out the most obvious effective area bycomparing the displacement, velocity and acceleration response of rail. Analysis the vibrationresponse of rail in different levels of speed, gained the result about the influence of runningspeed acted on the orbit vibration.3. Based on the acoustic boundary element theory, built a BEM model combined withANSYS rail model by using LMS Virtual.Lab software. Taking the rail vibration response asdisplacement boundary conditions and predict the noise. By comparing the predict result ofacoustic radiation efficiency with other literatures to confirm the feasibility of noiseprediction simulation.4. The boundary element model is divided into three parts as rail head part, rail web partand rail bottom part. Analysis the ATV (Acoustic Transmission Vector) of rail is based on thenoise test of rail, then built relationship between the space voice field and surface of trail, themost influential position to the surface via can be preliminary determined and provide a basisfor following Panel acoustic contribution number analysis.5. As to the selected structural areas in the rail, the present study conducts the acousticpressure contribution analysis and determines the value for pressure contribution from eachpanel and the panel area that provides the most pressure contribution. In order to make theacoustic contribution number analyses for the parts then confirm the maximum area of panel,find the main area of rail noise in the meantime. At last, verify the main part of rail noise...