Analysis Of The Vibration Reduction Characteristics Of Steel Spring Floating Slab Track

With its high efficiency,safety and reliability,small investment in construction and low maintenance cost,the high line of urban rail transit becomes an important railway line.But because of the elevated rail directly exposed to the environment,when the subway train vibration noise problems caused by the severe impact of the nearby residents work life,in order to solve the problem people devised a variety of vibration damping track,this paper chooses the vibration reduction performance good steel spring floating slab track study as the research object.The main research work of this paper is as follows:1.According to theory of finite element,vehicle-track-bridge coupled vibration theory,respectively established the box beam finite element model of floating slab track(FST)and vehicle.the model,joint simulation method is used to realize the vehicle.the,wheel/rail force,and to explore the natural vibration characteristics of box girder bridge under the subway train load transient characteristics,analysis of the vibration response of box beam.2.Based on the established finite element model of box beam,the Block Lanczos modal extraction method on the natural vibration analysis,and analyzes the steel spring stiffness,steel spring spacing,the density of the floating slab and fastener stiffness of elevated steel spring floating slab track the influence of natural frequency.The results show that the stiffness of steel spring floating slab track(FST),spacing,the density of the floating slab influence on the natural frequency of the system is more obvious,steel spring stiffness and spacing for the influence of the system low frequency than the high order frequency,the influence of floating slab density change is to change the quality of the structure,to achieve better effect of vibration damping noise reduction can be meet clearance of track structure under the condition of appropriate increase the density of the floating slab to reduce the system natural frequency.The change of the buckle stiffness has little effect on the frequency characteristics of the system,and it is not a key factor to study the inherent frequency characteristics of the floating slab track system.3.Through to the elevated steel spring floating slab track and vibration response of the comparative analysis of common rail,can see elevated steel spring floating slab track compared to the normal track of box girder bridge vibration reduction effect is very obvious,and through the increase of rail and track vibration level to reduce the vibration of the bridge,and fully illustrates the elevated in a strict in vibration noise of the special location,the floating slab track is a good choice.4.Elevated steel spring floating slab track as the main research object,using vibration acceleration level as indicators to evaluate steel spring stiffness,spacing and density of the floating slab,fastener stiffness parameters on the orbit,the influence law of bridge vibration characteristics,and the steel spring stiffness to the influence of the transfer function of floating slab track(FST)to do the analysis.The conclusions are as follows:Steel spring stiffness is affect the floating slab track system vibration level of the important parameters,in 1 ~ 10 hz frequency range of the floating slab vibration level generally decreases with the increase of steel spring stiffness,in 10 ~ 100 hz frequency range,the center line of the orbit,flange and web,the vibration of the beam bottom level decreases with the decrease of the steel spring stiffness.The change of the stiffness of steel spring has obvious effect on the transfer function.The smaller the stiffness of the steel spring,the lower the vertical transfer function value of the floating plate to the flange,the web and the bottom plate.Within the scope of the 4 ~ 8 Hz,the vibration of the floating slab level increases with the increase of steel spring spacing,within the scope of the 10 ~ 100 Hz,the vibration of box girder structure all pick up points level decreases with the increase of steel spring spacing.The change of floating plate density has little effect on the vibration level of steel rail,floating slab and bridge,but it decreases with the increase of steel spring density.In the frequency range of 1 ~ 50 Hz,the change of the coupler stiffness has no obvious effect on the vibration level of the pickup points of the bridge.Within the scope of the 50 ~200 Hz,the pick up point of vibration level generally increases with the increase of fastener stiffness,vibration level and rail bridge under the influence of fastener stiffness than on the vibration output point.