Influence of rail track properties on vehicle–track responses

This paper presents an investigation, using a numerical approach, of the dynamic response of the vehicle–track system as a function of the mechanical properties of high-speed rail track components. In particular, in this study the stiffness of the rail pad, ballast and sub-grade layer were considered as variable parameters. In order to assess their influence on the dynamic response during vehicle–track interaction, a sensitivity analysis was carried out. The analysis was undertaken using a simplified two-dimensional vehicle–track model, including the non-linear contact between wheel and rail, the track irregularities and several vehicle speeds. In total, more than 120 numerical simulations were performed, modifying, one at a time, the stiffness of the parameters. After processing the results, it was concluded that all the parameters considered have some influence, although the rail pad stiffness is the variable showing the highest influence. It is concluded that the procedure described is of use in optimising track design and reducing the dynamic response.