A frequency domain analysis framework for assessing overturning risk of high-speed trains under crosswind

This study introduces a frequency domain analysis framework for assessing overturning risk of high-speed trains under the excitations of crosswind and track irregularities. Based on a comprehensive numerical computation, closed-form expressions are established for the power spectra and coherence of turbulence relative to a moving vehicle influenced by vehicle speed and direction. The wind turbulence at stationary positions fixed on the ground is characterized by Kaimal or von Karman spectra and Davenport coherence model or a more general coherence model. These closed-form expressions facilitate the quantification of vehicle dynamic response by the effective spectral analysis approach, and also provide essential turbulence information for wind tunnel studies of aerodynamic forces on stationary vehicle models. Closed-form formulations are also presented for computing vehicle dynamic response by focusing on two dominant modes relevant to vehicle overturning risk. The vehicle overturning risk analysis leads to a determination of characteristic wind speed curve for a given vehicle running speed with a target overturning probability. Examples are presented to illustrate analysis framework and to investigate the influence of various parameters including the vehicle model on the vehicle response characteristics.