Research On Rail Dynamic Vibration Absorber Based On Particle Damping Mechanism

With the development of China’s economy,the demand of residents’ travel is increasing,the original bus and other facilities have been difficult to meet the residents’ travel,and the popularity of private cars leads to more and more congestion of road travel.Therefore,according to the traffic requirements of urban residents,urban rail transit is gradually popularized.Because of its punctuality and large traffic volume,it has gradually become the main mode of travel in the city.However,the primary problem caused by the construction of urban rail transit is vibration and noise.The boundary between rail and buildings is getting closer and closer.Some are close to buildings,and some cross through buildings.Most of the underground tunnels of rail transit are in line with the main road,which greatly affects the lives of the surrounding residents.Therefore,it is very necessary to solve the vibration and noise problem of rail transit for the development of rail transit.The main research contents of this paper are as follows:(1)firstly,the frequencies of the first two pinned pinned resonance modes of the rail are calculated,and the main body of the dynamic vibration absorber is designed based on the target control frequency band,and the finite element model is established to optimize the structural parameters.(2)In this paper,the particle damping dynamic absorber structure is simulated and analyzed,and the discrete element software is used to model the particle part.The energy dissipation effect of particle damping under different working conditions is calculated,and the damping ratio of particle damping structure under different frequency loads is calculated.According to the calculated frequency dependent damping ratio,the finite element rail model is established to calculate the rail velocity admittance and vibration attenuation rate before and after the installation of particle damping dynamic vibration absorber;The boundary element model is established to analyze the rail sound radiation before and after the installation of particle damping dynamic vibration absorber.The noise reduction effect of particle damping dynamic vibration absorber and its influence on spatial noise radiation are studied.The simulation results of finite element and boundary element are used to calculate the sound power level of rail,and the noise reduction effect of particle damping dynamic vibration absorber is analyzed.(3)In the laboratory,the vibration attenuation rate and the effect of vibration reduction and noise reduction of solid particle damping dynamic vibration absorber are tested.The test results of vibration attenuation rate are compared with the simulation results to verify the correctness of the model.According to the actual test results of vibration and noise reduction,the effectiveness of the designed particle damping dynamic vibration absorber is proved.