Research On Vibration Reduction Performance And Structural Optimization Analysis Of Floating Rail Damping Fasteners

In recent years,the rapid development of urban rail transit has brought convenient transportation and also produced noise and vibration pollution.With the improvement of people’s requirements for the quality of life,how to reduce the vibration and noise in rail transit has become an urgent problem.A large number of damping measures have been adopted for rail transit in various cities in China,among which damping fasteners have been installed on rails that require vibration damping.However,compared with other forms of damping fasteners,there are relatively few domestic and foreign studies on the structural composition,installation process,line test,and use of floating rail damping fasteners.Lack of understanding of its structural composition,vibration damping performance and problems solving during use.Based on this,this paper takes floating rail damping fasteners as the research object,and focuses on the research of the damping performance of floating rail damping fasteners,and improves and optimizes its structure.The main research work includes the following aspects:(1)The floating rail damping fasteners are summarized.The structure and performance characteristics of the floating rail damping fastener are introduced,the design principles of vibration isolation and resonance of the floating rail damping fastener are analyzed,and found out its existing problems(rail corrugation)and possible causes.(2)Establishment of finite element model.An accurate finite element model of the tuned damper floating rail fastener is established,and the correctness of the model is verified by comparison between simulation and experimental results.Based on the single floating rail fastener model,a finite element model of the track with floating rail fasteners was established.(3)The track characteristics and vibration reduction performance of the tuned damper floating rail fastener track and the common fastener track are compared and analyzed.The track characteristics and vibration damping performance of the tuned damper floating rail fastener track were analyzed using the results of finite element modal analysis,white noise excitation,and test data.The results show that the tuned damper floating rail fastener can significantly reduce the vibration level of the track bed,and the built-in tuned system can effectively control the rail vibration caused by the low support stiffness of the rail itself.(4)The problems of the existing floating rail damping fasteners were improved and optimized from three aspects of fastener structure design,structural optimization and field maintenance rectification.In terms of structural design,an insulation limit block was designed to limit the torsion of the rails,thereby suppressing the occurrence of abnormal wave wear of the rails.In terms of structural optimization,the influence parameters of the mass material,cross-sectional shape,and layout method were analyzed.The optimal structure scheme was put forward.In terms of on-site maintenance and rectification,a scheme for scientific installation and maintenance of fasteners was proposed.