Study On Vibration And Noise Reduction Characteristics Of Light Rail Wheels Damping Ring

With the rapid development of trail transit in today's world,the light rail plays an important role as one type among the variety of urban trail transits which are the closest related to our life.While facilitating people's travel and solving the urban traffic congestion,light rail also brings a series of problems,one of which is the noise radiation.Therefore,certain measures must be taken to control the main noise source of light rail trains-wheel-rail noise.In this paper,a friction damping ring applied to the wheel of light rail train was designed based on the principle of friction damping.The effect of vibration and noise reduction is verified by experimental test.The finite element method was used to analyze the modal distribution characteristics of light rail train wheels.A friction damping ring was designed by the energy dissipation mechanism of it.The modal distribution of the damping ring was analyzed by the finite element method.The mode of the damping ring was divided into axial mode,radial mode and axial radial coupling mode.The modal data in four states of empty wheel,outer side mounted damping ring,inner mounted damping ring and bilateral mounted damping ring,were tested.The relationship between the modal parameters,modal frequencies,modal damping ratios and the number and location of damping rings was analyzed.The results show that the modal vibration mode and the modal natural frequency of the wheel with the damper ring became smaller,but the modal damping ratio was increased.At the same time,the influence of the different mounting positions on the modal damping ratio of the wheel was different.In general,the effect of the double mounted damping ring on both sides was better than that of the single side mounting damping ring.The vibration response data before and after the wheel mounting damping ring were tested and analyzed.By analyzing the vibration response data,the damping effect of the damping ring on the frequency of the wheel is obtained.The results show that the damping ring on the outside is better for the low frequency,wihle the inner mounting damping ring is better for the high frequency.The effect of installing damping rings on both sides is equivalent to the superposition of damping rings inside and outside.Based on the noise radiation theory,the frequency characteristics and spatial distribution characteristics of the wheel mounted damping ring were tested and analyzed.The frequency characteristics of the noise were showed in the form of 1/3 octave.The test results show that the frequency characteristics of the noise were consistent with the frequency distribution characteristics of the vibration,which means,the damping ring reduces the sound by reducing the wheel vibration.The spatial distribution characteristics test results show that the surface sound pressure distribution at the part frequency of the wheel was changed after the damping ring was installed,for example,the maximum sound radiation position at the part frequency was changed from the web to the wheel hub near the wheel,while the maximum sound pressure value at the other frequency was reduced after the damping ring was installed.The test results show that the method of reducing the noise of light rail wheels by friction damping ring is effective in certain aspects and is worthy of application.