Research On Decay Rates Of Railway And The Technology Of Its Absorber

The vibration and noise of track system are the problems that can not be ignored in the normal train operation,especially in the 50 ~ 2500 Hz,the rail is the main radiation source of noise.Because of noise and vibration attenuation is closely related to rail vibration rate is an important index for evaluating the different trajectory model of vibration and noise reduction,so this thesis is centered on the discussion,analysis of various parameters on the impact,on the basis of optimization design of dynamic vibration absorber.The simulation of three typical track model in Ansys,according to the weighted amplitude ratio calculated their decay rate,and compared with the theoretical model of discrete support,pointed out that the amplification effect of the theoretical modeling,then according to the low attenuation area to determine the vibration absorber to frequency range.On the dynamic vibration absorber with the theoretical model,research the quality,stiffness and damping loss factor to specific effects of band attenuation,interference due to the vibration of Pinned-Pinned appears a trough,need to optimize the parameter set to the highest trough,to improve the broadband characteristics better attenuation rate.According to the optimized stiffness and damping loss factors,the viscoelastic parameters of the required rubber are optimized by backstepping in Ansys.Good design of dynamic vibration absorbers installed in the laboratory,before and after using modal method to calculate the decay rate,steel rail,rail vibration,inherent frequency dispersion curve changes little,while the modal damping ratio and the change of decay rate is similar to that of the attenuation rate increased is verified by experiment of rail.Further noise tests show that the change of attenuation rate and the change of sound pressure level are synchronous,and the dynamic vibration absorber is effective in vibration reduction and noise reduction.