Srudy On The Vibration And Noise Of The Trough Girder Beam Bridge Induced By Train Load

Recently,China began to develop urban rail transit,in order to alleviate the problem of urban traffic congestion.Because of the viaduct has the advantages of short construction cycle,low cost of construction and operation,which gradually takes on more and more traffic flow.However,the viaduct structure is usually close to the building,and its radiation vibration and noise has become an important factor restricting the development of urban rail transit.Therefore,it is very urgent to study the vibration and noise of viaduct bridge structure,which has important practical significance.This paper takes a proposed rail trough-girder beam bridge as the research object,analyze trough-girder beam structure-noise,from the perspective of acoustic contribution,then,explores the bridge structure parameters and vehicle parameters influence on structure noise,it provides a theoretical support for the methods of reduce the viaduct Trough Girder Bridge vibration and noise in Urban Rail Transit.The main research work of this paper is as follows:1.On the basis of summary the urban rail transit development current situation and its series of problems,besides,expounds the necessity of the study on the trough-girder beam bridge structure vibration and noise in this paper.From the calculation analysis method of bridge structure noise(finite element method;boundary element method;statistical energy method and modal superposition method;infinite element method)and study of bridge structure noise control two aspects,summarized the domestic and foreign situation,and puts forward some problems need further research.This paper presents the main research contents and technical route,construction of rail transportation trough-girder beam bridge structure finite element boundary element coupling sound analysis calculation flow chart.2.Combining the vehicle track bridge coupling vibration theory and finite element calculation flow chart of the relevant theory of boundary element coupling sound principle and acoustic radiation and noise structure,puts forward the relevant model of trough-girder beam vibration and acoustic radiation prediction(trough beam finite element model and boundary element model of train vehicle model of vehicle bridge coupled model)method,coupled by the joint simulation,obtain the wheel rail excitation force.Then the natural vibration characteristics of the bridge structure and the transient characteristics of the bridge structure under the action of train load are studied,and the structural vibration response of the beam bridge under train load is analyzed.3.In view of the bridge structure-noise introduced by the subway trains passing through the viaduct,respectively from two angles of steady and transient noise,bridge elevated trough time domain characteristics;spectrum characteristics and spatial distribution is comprehensive analyzed.Besides,based on the steady radiation of bridge structure-noise,characteristic frequency weighting coefficient and field weight coefficient method is introduced,a method to analyze the bridge panel acoustic contribution is presented,comprehensive acoustic contribution of bridge deck is researched in the complex environment,which provide a theoretical reference to reduce bridge structure-noise.4.At the aim of bridge structure-noise effect parameters,which have uncertainly conclusions,then,combining the orthogonal experimental design method,analysis the influence of key parameters on the bridge structure-noise from the view of transient noise radiation.Besides,on the reviewed of the bridge resonance phenomenon when the train passes through the bridge at different speeds,resonance analysis a 30 m trough-girder beam bridge,discussing the vibration response and the radiation noise of trough-girder beam bridge.5.Based on the integrated acoustic contribution analysis of trough-girder beam bridge,obtaining key panel bridge structure noise,then,discussing the influence of different structural parameters(bottom/web)on the spectral characteristics and spatial distribution of the radiated sound field of an elevated beam bridge,which provides a new way and a new idea for the control of bridge structural-noise.