ABSTRACT
Railway track is a basic technical structure essential for train operations, with the purpose of guiding trains to run smoothly, to carry dynamic loads from wheel-rail interaction and to transmit the dynamic loads to the infrastructure. Therefore, track service condition and its dynamic performance have significant influences on the running stability and ride comfort of trains. This chapter focuses on the dynamics and modelling of various railway track structures, as well as the interaction between track and train. Initially, the track dynamics modelling, especially in the train-track interaction analysis, is briefly reviewed. Then, the most typical and commonly used dynamics models for ballasted track and slab track are described in detail, with emphasis on the equations of motion of track components. Further, the modelling methodology of train-track interaction is discussed, based on the framework of vehicle-track coupled dynamics theory. This includes how the vehicle and track subsystems are spatially coupled at the wheel-rail interfaces and how the large-scale nonlinear system is solved. System excitation descriptions are then presented, including models for impact loads, harmonic loads, random track irregularities and the comparisons of track irregularity power spectrums for high-speed railways worldwide. On this basis, dynamic properties of track structures under impact loads and random vehicle dynamic loads are discussed. Finally, to elucidate the application of vehicle-track coupled dynamics in railway track design, an example of developing a vibration-attenuated track for an urban rail transit application is presented.
