3D Modeling of Slab Track to Study Track Frequency Response

As time went on, ballasted tracks have been replaced with slab tracks due to the extreme limitations of ballasted tracks (e.g., speed and capacity limitations) and high costs of repairing these tracks. But, by using the slab tracks, new dimensions have been presented in dynamics of these lines. The aim of this research is to study the effects of dimensional and mechanical parameters of the track components (i.e., thickness and elasticity modulus of layers) on vertical dynamic response of a three-dimensional model using finite element method. The Rheda 2000, as one of the most widely used tracks in the world, is investigated in this study. The finite element analysis is conducted based on two categories: frequency analysis and steady-state dynamic analysis. The natural frequencies and corresponding vibration modes are extracted by using frequency analysis. Also, frequency response functions of the track are extracted by using steady-state dynamic analysis. Results showed that by decreasing the elasticity modulus of track components, the resonance frequencies decreased and the vertical frequency responses of the track increased. Moreover, increasing the thickness of layers led to the increased resonance frequencies and the decreased vertical frequency response of the track. The elasticity modulus of hydraulically bonded layer and the thickness of concrete bearing layer in Rheda 2000 are the most effective parameters on dynamic behavior of this slab track.