Numerical simulation of train-track-bridge dynamic interaction

The topic of train-bridge system dynamics is gaining great importance due to the development of high speed train transportation all around the world, with regard to both the design and opening of new lines, and the renewal of the existing ones. Short and long span bridges, continuos beam viaducts, cable stayed and suspension bridges are part of many high speed lines. Their analysis, in the first design stage, and their verification, can be carried out by means of numerical simulations. Many problems are related to the interaction between train and bridge, involving global and local interaction. According to the investigated problem, several level of details on the modelling of train and bridge can be used, in order to find a compromise between computational time, on one hand, and accuracy and significance of the simulated results on the other. The numerical method for train-track-bridge interaction simulation, which fits with the above mentioned requirements, developed during the years at Politecnico di Milano, is presented in this paper, together with some validation example.