The Vibration Reduction Performance Analysis On Ladder Track System

City expansion and technology development make the traditional public traffic can't afford so many people. However, with high speed, punctuality, and big capacity, urban rail transit system offered the way to solve the traffic jam. Therefore, development of rail transit in the major cities in our country has been generally recognized. In general, urban rail transit system (subway) run in the densely populated districts, so subway's running impact on the environment has been drawing increasing attention. How to solve the impact on the buildings produced by subway's vibration and noise becomes an increasingly important issue.The parameter's design of track structure has great influence on decreasing vibration. The parameter of ladder track including stiffness, damper and the Natural Vibration Frequency are key factors to decreasing vibration. Because the rail system is very large and the coupling of its reaction are complex, it is difficult to reflected the real operating of the train by numerical computation, Recent years, the finite element method and related software have make great progress, which offered a way to solve the complex computation.In this paper, the use range and the present situation of the international research are investigated, and the damping principle of ladder track system is analyzed. The research of ladder track system lack relatively in China, and the track dynamics and analysis model of track structure are applied to set up the finite element mode of ladder track and fixed track, with the assistance of the large structure calculation software called ANSYS. That, the change of stiffness and damper how to affect the track system's vibration and simulate it to work in different situations in modal analysis and dynamic calculation are analyzed. The vibration and dynamical characteristic of these two kinds of track systems are compared, and relative measurement about vibration and noise decreasing are brought forward.The conclusion of this paper shows that ladder track system has better vibration reduction performance, its vibration reduction efficiency is double than fixed track, it worth be promoted in domestry.