Numerical study of dynamic response of railway vehicles under tunnel exit winds using multibody dynamic simulations

The dynamic responses of railway vehicles under crosswinds are investigated by using multibody dynamic simulations and compared with the experimental data. A new gust model is also proposed to predict aerodynamic forces acting on railway vehicles under tunnel exit winds. The dynamic responses of a model vehicle under tunnel exit winds are firstly predicted by multibody dynamic simulations and the predicted rolling angles of the vehicle by the identified structural parameters show good agreement with those from the running vehicle test. The dynamic responses of a commuter rail under natural winds are then studied and the calculated wheel unloading ratios match favorably with those from the field test. Finally, a dynamic amplification factor (DAF) for railway vehicles under tunnel exit winds is proposed and systematically investigated. It is found that DAF decreases as the passing time as well as the damping ratio and natural frequency of railway vehicle increase. A simple formula is also proposed to predict DAF of railway vehicles under tunnel exit winds. •A new gust model is proposed to calculate the side force on the railway vehicle induced by unsteady winds.•The unsteady responses of railway vehicles are investigated and validated by the experimental data and the field measurement.•A dynamic amplification factor is proposed to evaluate the effect of the unsteady response of railway vehicle under tunnel exit winds.