A substructure approach for the dynamic analysis of train–track–bridge system

The dynamic interaction between a running train, the track structure and the supporting bridge is investigated resorting to substructure technique. The train is idealised as a sequence of identical vehicles moving at constant speed. Both the rails and the bridge are modelled as Bernoulli-Euler beams, while the ballast is characterised as a viscoelastic foundation. A variant of the component-mode synthesis method is proposed to couple the continuous (rails and bridge) and discrete (train) substructures. Numerical investigations have demonstrated the accuracy and efficiency of the procedure, which allows to compute simultaneously the dynamic responses of the train, rails and bridge.