Coupled numerical modelling of railway track substructure with vehicle-track interaction

The track substructure is a vital and essential part of the railway track system which supports the track, and its properties have a strong influence on the overall track behaviour. In the research presented in this paper, a methodology for coupling the numerical models of the railway superstructure with substructure part is developed. The dynamic interaction between vehicle and railway track is presented taking into account the complexity of the modelling of the ballast bed, railpads, under sleeper pads and its effect on the determination of the overall track stiffness. The paper presents a framework to investigate the dynamics of overall vehicle-track systems with emphasis on theoretical modelling of the track substructure and superstructure components as well as numerical simulation of modelled solutions. A connection has been established between the multibody simulation package, used in the dynamic analyse of the whole vehicle-track system, and the finite element software used in the analysis of the track substructure. Then, the track dynamic properties have been updated simultaneously to the multibody simulation program for each track section. The proposed methodology has been used in the dynamic analysis of different track designs for increased axle load applications.