The Study Of Dynamic Stiffness Of The Transition Section Between Ballasted Track And Ballastless Track

Dynamic stiffness of the track is an important dynamic property parameter of track structure, as a result of dynamic action between wheel and rail, the track stiffness which measured by the dynamic stiffness is more reasonable. Previous studies of the transition section are static stiffness, in this paper, take the transition section between ballasted track of the roadbed and Züblin ballastless track as an example, to study the dynamic stiffness of the transition section.At the conclusion of the previous model of the transition section, in accordance with the actual situation of the track structure, establish mechanical model to study the dynamic stiffness of the transition section. In the model, consider the activity of the train as harmonic load; rail as Timoshenko beam on the basis of a flexible point support; fastener as linear spring and damping components; sleeper, ballast bed of ballasted track, roadbed, ballast bed board of ballastless track and concrete base, etc as entity.Use the finite element method to discrete the mechanical model of the transition section, rail divided according to the actual space of the fastener node, fasteners for the spring element, other track structure simulated by the physical element.Analyse dynamic stiffness characteristics and influence factors of the high-speed ballasted track and Züblin track with dynamic frequency-domain analysis method. The results show that the fastener stiffness, damping, suboccipital pad and sleeper configuration have a large impact on the dynamic stiffness of the ballasted track; But the dynamic stiffness of the Züblin track mainly affected by the effects of fastener stiffness and damping.Analyse the static stiffness transition plan between ballasted track and ballastless track, and point out the situation that the static stiffness transition plan can not make the dynamic stiffness transit gently. According to the law of the impact on the dynamic stiffness by changes in the track structure and parameters, adjust the stiffness transition plan, finally can get relatively more reasonable plan on terms of the dynamic stiffness transition.Finally, the paper summarizes the findings and put forward some of the inadequacies and the problems needed further improvement.