WAVE FINITE ELEMENT METHOD FOR COMPUTING THE DYNAMIC RESPONSE OF RAILWAY TRANSITION ZONES SUBJECTED TO MOVING LOADS

The dynamics of a railway track on transition zones is the subject of numerous analytical and numerical researches. This article presents a new development of the wave finite element method for such a structure in order to reduce the calculation time. We consider a transition zone which is between two half infinite periodic tracks (which could be of different types, e.g. a zone between ballasted and non-ballasted tracks) and train loads are represented by concentrated moving loads. We applied WFE for each half periodic track to obtain the relationship that links the responses of the boundary zone of each periodic part with the help of the wave analysis. Then, this relationship is combined with the dynamic equation of the zone to get the global dynamic equation of the whole railway track. This technique permits to reduce the degrees of freedom (DoF) of the track to those of the transition zone. Numerical studies show the influence of the geometrical and mechanical parameters of the transition zone on the mechanical response of the track with a transition zone compared to a uniform track.