Study on Mitigation Measures to the Vibration of Vehicle-Track System

With the development of urban rail transit, more and more environmental problems come out, especially the impact of vibration and noise induced by transit lines on people who live around metro viaducts. In order to improve the vibration condition of bridge and surrounding buildings, most mitigation measures are applied without considering vehicle vibration. The past research has shown that these measures tended to enlarge the vibration of rail or vehicles. Aiming at improving this situation, a numerical finite element model of Wheel-Track-Bridge coupling system is built in this article. Vibration characteristics of bridge, wheels and rail can be obtained to validate the previous research results. Comparison of vibration levels of the whole system with different track structure stiffness, it is proved that lowering fastener stiffness can only reduce the vibration of bridge but enlarge that of rail and wheels. This paper proposal a new method to weaken the vibration of both bridge, rail and wheels simultaneously. The conceptualization of dynamic vibration absorber was put forward to absorb vibration of the whole system of elevated lines. A simplified two dimensional model was built to test mitigating vibration performance of this kind of absorber. After numerical analysis, the results indicated that dynamic vibration absorber would decrease vibration level of bridge effectively while not enlarge the vibration level of rail. Its mass and stiffness are the principal parameters related to its working property and is also where the key lies in designing this component.