Analysis Of Rail Vibration Characteristics Under Different Frequencies

In order to control the rail vibration and the its radiated noise due to vibration, and the rail diseases caused by rail vibration more effectively, we need to know the rail vibration characteristics, vibration modes, and transfer characteristics under different frequencies. Summing up the domestic and international rail vibration models and the researches, considering about the limitations of the rail beam models and short solid rail models in high-frequency dynamic analysis,this paper established a 120m-long rail solid finite element model. Analyzing the rail vertical and lateral vibration characteristics, vibration transfer characteristics, mode shapes between 0-20kHz,and the influence of damping to rail vibration transfer characteristics. Analyzing the rationality of rail Euler beam model, Timoshenko beam model and long solid model under different frequencies. Besides, established a rail-constrained damping vibration absorber model to study the control effect to the rail vertical and lateral vibration under different frequencies.According to the analysis, the vibration mode of the rail under rail resonance frequency is similar to static bend deformation of the rail, when the frequency is above the resonance frequency, the rail vibration mode shows more waveforms. When the vertical and lateral vibration frequency increased, the rail cross-section had deformation.Rail Euler beam model is applicable for vertical vibration before the rail cross-section deformed. In the lateral vibration analysis, the beam model can not reflect the torsion deformation caused by the lateral load at the rail head, there arc difference between the results of beam models with the long solid model's.High-frequency vibration in the rail has a long transfer distance, in the same frequency, the lateral vibration can travel much longer than vertical vibration along the rail. The damping of rail pad has a obvious inhibition of the rail vibration which has more waveform, increasing the damping can reduce the vibration travel distance and the vibration amplitude.The effect of constrained damping rail vibration absorber in this paper has no obvious effect on low frequency vertical vibration, the effective frequency of the absorber to rail vertical vibration is the peak frequencies above the first pinned-pinned vibration. Installation of absorber increases the lateral bending stiffness, so the torsional deformation of the rail decreases. This absorber has effect on most lateral vibration, and has a remarkable damping effect on the rail waist.The analysis in this paper overcomed the previous insufficiency of rail vibration analysis, given the vibration characteristics, transfer characteristics and its influencing factors between 0～20kHz. Provide a theoretical basis for the further study of rail vibration, noise and vibration control and other issues related to the vibration.