Numerical study of tornado-induced unsteady crosswind response of railway vehicle using multibody dynamic simulations

The tornado-induced unsteady crosswind responses of railway vehicles are investigated by using multibody dynamic simulations. Firstly, a tornado-induced aerodynamic force model is proposed by using the equivalent wind force method and the quasi-steady theory and validated by the experimental data. The Uetsu line railway accident caused by tornado winds on December 25, 2005 is then investigated by the proposed tornado-induced aerodynamic force model and the multi-body dynamic simulation. The predicted accident scenes show favorably agreement with those obtained from the accident survey when the maximum tangential velocity of tornado is around 41 m/s and the core radius is 30m. Finally, the dynamic amplification factor (DAF) for railway vehicles in tornado winds is systematically studied and it increases as the passing time decreases. It is found that the DAF can be effectively suppressed as the damping parameters increase while it decreases slightly as the natural frequency increases. A simple method to predict the DAF is also proposed based on simulation results.

Automated summary

The study investigates the unsteady crosswind responses of railway vehicles induced by tornadoes using multibody dynamic simulations. It proposes a tornado-induced aerodynamic force model and validates it with experimental data. The study also examines the Uetsu line railway accident caused by tornado winds on December 25, 2005, with predicted accident scenes showing agreement with survey results, especially when considering specific tornado parameters. It systematically analyses the dynamic amplification factor (DAF) for railway vehicles in tornado winds, finding that DAF increases with decreasing passing time and can be effectively suppressed by increasing damping parameters.