Dynamic Analysis Of Rational Stiffness Of Damping Ballastless Track

With the construction of the Passenger Dedicated Lines and development of the Urban Railway System, since its high stability, uniform stiffness, fine durability, and less maintenance, ballastless track becomes the trend of railway structure. Many countries in the world deploy plenty of manpower and financial resources on ballastless track research, and have developed a hundred or more types of ballastless track structure. But environmental vibration and noise problems caused by ballastless track are more evident, and have seriously influenced people's work and life, which have drawn much attention of related departments. Therefore, the low vibration track is more and more used in many countries because of its well performance of reducing noise and vibration, but because of its numerous structure types and parameters, how to describe and determine the reasonable stiffness matching relationship and vibration reduction performance in dynamics is of great value in both theory and engineering application.Firstly, from the viewpoint of reducing noise and vibration, the article have analyzed the mechanism of vibration reduction, and have investigated the relationship among force, acceleration and displacement as the evaluation indexes of the track dynamic behavior using the equivalent three DOF model. It is showed that there is a good agreement between using force as the track dynamic behavior evaluation index and using acceleration and displacement. This provides theoretical basis for the low vibration track reasonable stiffness analysis.Secondly, taking Vibration reducing slab track,Ladder Track, Floating Slab Track,Elastic Bearing Block Track, Elastic Long Sleeper Buried-Type Track, Damper Fastener Track and four types of damping fasteners as the research objects, and using FEM program ANSYS, the article have modeled each kind of track structures based on real track structure. Dynamic behavior of each type of track is treated under impact load and the reasonable stiffness matching relationship among components of track are determined.Finally, the vibration reduction performance of each kind of track and fasteners are analyzed and compared within the limit of reasonable stiffness. The result demonstrates that Floating Slab Track does the best in reducing vibration, followed by Ladder Track, Bearing Block Track, Elastic Long Sleeper Buried-Type Track, Vibration reducing slab track, Damping fasteners. The research achievement of this article is of reference value for the type selection of low vibration track and stiffness designment in practical engineering application.