Dynamic response of vertical maglev train-bridge systems considering aerodynamic self-excited forces

The high-speed maglev train (HMT) has a pronounced fluid-structure interaction, which is one of the controlling factors for the safety and comfort of HMT. To investigate the effect of fluid-structure interaction on the HMT system, firstly, an aerodynamic self-excited force model of HMT, which is drawn on the experience of bridge flutter theory, was proposed. The identification method of the self-excited force coefficient and the corresponding time-domain processing method of the self-excited force were introduced. Secondly, a three-dimensional CFD model of the high-speed maglev train-bridge (HMTB) systems was presented. The accuracy of the numerical model was validated, and the self-excited force coefficients of the HMT were identified by the forced vibration method. Finally, a coupling vibration model of HMTB systems considering aerodynamic self-excited forces was developed, and the effect of aerodynamic self-excited forces on the vertical dynamic response was analyzed. The results indicate that the self-excited lift has only a minor influence on the vertical response at the carbody center. Moreover, owing to the positive value of the self-excited force coefficient A * 2 in the tail vehicle, the self-excited pitching moment introduces negative aerodynamic damping, which amplifies the pitch response and consequently increases the vertical responses at the carbody ends. These findings highlight the necessity of considering aerodynamic self-excited forces in the dynamic analysis of HMTB systems.