Research On Dynamic Performance Of Slope-type Low Vibration Track

The low vibration track has the advantages of good vibration damping effect and good noise reduction performance.It has been widely used in heavy-haul railway tunnels.The newly developed slope-type low vibration track has good geometric position retention,improving the stress state of the boot and enhancing the stability of the track structure than the traditional type.At the same time,due to the change of the structure of the elastic bearing block,the dynamic characteristic of the track system has changed.So it is necessary to study the dynamic performance of slope-type low vibration track.In this paper,the dynamic performance of slope-type low vibration track is studied from three aspects: inherent dynamic characteristics of track,impact dynamic response of falling wheel-set and dynamic response of the train.It provides a basis for optimizing the dynamic performance of slope-type low vibration track,and it is significant for improving the design theory of track structure.The main research contents are as follows:(1)The slope-type low vibration track model was analyzed.On the basis of this,from the perspective of the inherent dynamic characteristics of the track,the natural frequency and mode shape was calculated,and the effects of the rail parameter variation on the natural frequency were analyzed.It is concluded that increasing the thickness of the track bed and the length of the support block is significant to improve the inherent dynamic characteristics of the track.(2)From the perspective of the dynamic performance of the track under wheel load drop,using the test of wheel load drop simulation model,the influence of different under-rail stiffness and under-block stiffness on the track dynamic response index was calculated and analyzed.It is concluded that stiffness matching properly is important for dynamic performance of track by using wheel load drop.(3)From the perspective of the dynamic performance of the track under train load,the influence of the rail parameter variation on the dynamic response of the track was calculated and analyzed by using the coupled vehicle-track system dynamic model.The dynamic response of track under different driving conditions was calculated through the relevant parameters matching reasonably.According to the requirements of the relevant standard,the rationality of parameter setting was verified.