Research On Noise Control Of Train Wheel And Design Of Noise Reduction Block

The rapid development of high-speed railway provides great convenience for people's commute,but the noise pollution caused by railway traffic becoming increasingly appearing.Noise pollution of the railway traffic will cause both discomfort and anxiety of passengers,besides,which significant influenced on the living environment of residents around the railway.For solving the noise problem of railway traffic,according to wheel-rail vibration mechanism and characteristic,designed a sandwich-type de-noise block of train wheel,this master's thesis conduct research for wheel radiation noise,the research projects contents include:1.The analysis of wheel vibration and noise radiation.Built wheel FEM analysis model,The modal parameters of wheels are obtained,these modals contain 6 significant modals,solved vibration response of wheel structure by modal superposition method.Computed wheel noise radiation by FEM,when the wheel vibration frequency rage in 0~600Hz,noise radiation efficiency and vibration frequency are in the direct proportion,when frequency upper than 800 Hz,the noise radiation efficiency of radial excited wheel is nearly 1 and bigger than axial excited wheel.Calculated average sound pressure of wheel noise radiation,which vibration energy heavily focus on 1600Hz~5000Hz,analysed outer sound filed pressure cloud map,when wheel excited by radial force,the maximum sound pressure is 114dB(A).2.The schematic design of wheel vibration-noise control.Based on dynamic vibration mechanism and constrained damping mechanism,designed a sandwich-type wheel radial denoise block.By selecting material and different structure design diameters to comparing those elements,which shows 4 sheets and 2.5mm damper sheet are best.Adopted equation damp theory and centralized mass method,built wheel-block system analysis model to analysed modal,vibration response and noise radiation characteristic,predicting de-noise effect.The maximum sound pressure decreased 14dB(A),average sound pressure decreased 11.8(A)of installed de-noise block wheel.3.Wheel modal test.Constructed a platform of wheel vibration modal test,adopted hammering method and complex frequency field method for modal test.The different value between modal test and modal theory analysis are blow 4%.De-vibration and de-noise test were carried out for wheel de-noise,test results show de-noise block works well,the damping of whole wheel has increased about one order of magnitude,dominant frequency peak value has decreased 15-~40dB of vibration transform function.The sound energy magnitude of radial excite and axial excite decreased 11.9dB(A)and 14.3dB(A)respectively.4.Wheel sound radiation test.Built a platform of wheel sound radiation,adopted pendulum pulse excitation to get sound pressure magnitude and sound energy magnitude.Test results show: after install de-noise block,wheel's sound energy magnitude of radial excite and axial excite decreased 11.9dB(A)and 14.3dB(A)respectively.