Abstract
In this study, we investigate dynamic interaction between high-speed trains and a floating trackbed system (FTS) using coil springs. FTS is composed of concrete slab supported by coil springs. The trackbed is composed of a rail and a concrete slab, and those are modeled as freely-supported beams in this study. The railcar model in this analysis has 10 D.O.F. and is composed of a rigid carbody supported by springs and dashpots. We consider the vertical vibration and pitching motion of the carbody, and the random irregularities of the track. Dynamic response of the trackbed is analyzed by means of modal analysis using lower 20 modes of vibration. Dynamic interaction between the railcar model and the trackbed is taken into account. We employ parameters of a 10-car train and investigate vibration characteristics of FTS and carbodies for various train speeds and installation intervals of the coil springs numerically. The simulation results indicate the existence of the optimal intervals of the coil springs for the vibration isolation and the riding comfort.
