Abstract:
In high-speed trains, the driving safety and passenger comfort of the railway vehicle are negatively affected due to the problem of interaction between the train and the bridge. Among these problems are rail irregularities, flexible foundation effect, and external effects such as wind load and seismic loads. In this study, the dynamic interaction between the full train model modeled as 31-degrees of freedom and the bridge that can be modeled according to the Euler-Bernoulli beam theory was studied. The motion equations of the train and bridge beams have been derived with the Lagrange method, and the motion equations obtained have been solved with the fourth-degree Runge-Kutta method. The results obtained in this method were confirmed by two case studies previously conducted. The first four natural frequencies of the beam calculated using bridge parameters were determined, and the resonance velocities, which are the critical velocities of the beam-train system corresponding to this determined frequency, were calculated. Moving at resonance velocities, the train causes maximum acceleration amplitudes, especially in low damped beams. In this study, maximum dynamic responses were determined at variable velocities of the train, and it was understood that critical velocities were an essential concept in train-bridge interaction. It has also been found that well-damped beams reduce maximum dynamic responses. As a result, it was found that car body mass, bridge length, and train velocity significantly affect the combined train-bridge dynamic interaction.
