Research On Rubber Components Applied To Reducing Vibration And Noise Of Wheel-Rail

In order to solve the engineering problems of wheel rail vibration and noise in rail transit,three kinds of products are designed based on mechanism and theory of wheel rail vibration and noise reduction,which are wheel noise reduction block,rail vibration absorber and rail vibration isolator.The products were trial-manufactured,and the real effect of them was verified by tests.The theoretical calculation and test method of wheel rail vibration and noise were studied,and its characteristic parameters were also analyzed.Modal parameters,vibration frequency response and acoustic radiation characteristics were calculated with the FE model of a wheel.The modal test analys is was carried out by hammering method and complex frequency domain least square method on wheel vibration modal test-bed.Sound pressure level and sound energy level of wheel radiation were obtained with impulse excitation of swing ball on wheel acoustic radiation test-bed.Solution of reducing vibration and noise of the wheel was developed based on previous research findings.A sandwich wheel radial noise reduction block was designed based on the principle of dynamic vibration absorption and constrained damping.A simulation model of Wheel-Noise Reduction Block system was built based on equivalent damping theory and lumped mass method,and the simulation results show that the radiation sound pressure level of the wheel with noise reduction blocks could be reduced by 11.8 dB(A).Solution of vibration and noise reduction of the rail was also developed with two paths.First,a broadband rail absorber was designed based on the principle of damping dynamic vibration absorption.A Wheel-Rail dynamic model and a FE model of Rail-Absorber system were built,and the simulation results show that the radiation noise of the rail with absorber could be reduced by 8 dB(A).especially,the vibration and radiation on main frequency were significantly reduced.Second,the influence of vertical stiffness of rail vibration isolator on rail dynamic targets was analyzed with a Vehicle-Rail system dynamic model,and the reasonable range of stiffness was also determined.The wheel noise reduction block,rail vibration absorber and rail vibration isolator were trial-manufactured and verified on the test-bed and real rail.The test results show that with the noise reduction block installed on the wheel,the overall wheel damping increases by about one order of magnitude.The peak valu e of the main frequency of the vibration transfer function decreases by 15-40 dB,and the sound energy level decreases by 11.9-14.3 dB(A).The rail vibration attenuation rate increases by 9 dB/m with the vibration absorber on.Compared with the rail supported by ordinary fasteners,the vibration of the one supported by vibration isolator decreases by 9.9 dB on viaduct ballast bed,and the noise decreases by 6 dB(A).Especially,the vibration on the underground tunnel wall can be reduced by 12.1dB.