Study On Rail Vibration And Longitudinal Transmission Characteristic

In order to solve the problem of how far the rail vibration transmission can pass,First of all,we must grasp the rail vibration transfer characteristics.To solve this problem,this paper established an vibration analytical model of 81m long solid element rail based on research at home and abroad,researches the solid element rail vertical transfer characteristics and lateral vibration transfer characteristics between 0-40kHz,and gives the 1/3 octave frequency steady-state mode shapes of solid rail and rail excitation cross-section(top of rail top,side of rail top,rail web)displacement admittance chart.The effects of different stiffness,damping and sleeper spacing on the vertical vibration and lateral vibration of rail are analyzed and compared.At last,the maximum distance between the vertical and transverse vibrations can be obtained by calculating the attenuation rate.The results show that when the frequency is less than the vertical and lateral resonance frequency,the vertical and lateral stress deformation of the rail is equivalent to that of the static force.When the frequency is greater than the vertical transverse resonance frequency,the rail vibration deformation rapidly spread to the whole rail.With the increase of frequency,in the vertical vibration of rail flange will be the first to produce large deformation,and rail deformation mainly concentrated in the head part after tens thousand Hertz,in lateral vibration,large deformation firstly comes from rail head,and then the deformation is mainly reflected in the waist position.The farther the distance from the excitation point is,the larger the vibration attenuation is,the smaller vibration gap along the different positions of the rail is.The influence of the variation of the rail stiffness on the vertical and lateral vibration of the rail is mainly concentrated in the 5kHz before,and the stiffness change after 5kHz has no effect on the rail vibration.The damping of the rail has an influence on the vertical and lateral vibration of the full frequency rail.Although the sleeper spacing has an influence on the whole frequency,it only has a regular effect on the pinned-pinned vibration.At last,the transmission distance of vertical and horizontal vibration is studied.The influence of damping on the vertical and horizontal vibration transmission distance of the rail is studied.The larger the damping is,the shorter the distance is,but as the frequency increases,the influence of damping on the transmission distance becomes smaller.Then we calculated the attenuation rate,it is found that the transmission distance of transverse vibration is much more than that of vertical vibration,and the frequency points of the minimum attenuation rate of the two are different,but they all occur in the same position of the cross section of the rail.