Numerical Study of Railway Track Dynamics : Case of a Transition Zone

The main objective of this paper is to present an innovative numerical tool to represent the track and platform dynamic behavior under passing trains. Dynavoie is currently being developed for engineering purposes at SNCF. It is specifically designed to correctly reproduce the track and platform dynamic behaviors in the time domain. This model is based on the Finite Element Method (FEM), adapted to the railway track using model reduction techniques. Taking advantage of the periodicity of the track introduced by the regular sleeper spacing, one or several basic slices containing all the geometric properties of the structure can be identified. Static and periodic responses of these slices are computed. Then, reduction is performed using these deformations.Thus the number of degrees of freedom of the model is highly reduced. This reduction induces a decrease in computation time with limited accuracy loss in the representation of track dynamics. The methodology will be further described in this paper. The second novelty of this work is to use this model to analyze the dynamic behavior of a transition zone located in a French high speed line