桥塔尾流风作用下吊索尾流致振动模型与参数分析

Field observations indicate that for a large-span suspension bridge, the suspender influenced by the tower wake frequently experiences large-amplitude wake-induced vibrations. A single tower column and a suspender of a suspension bridge were investigated to reveal the vibration mechanism and provide theoretical guidance for engineering design and applications. First, wind tunnel tests of large-scale segment models were performed. The experiments replicated the wake-induced vibration of the suspender in the wake of the tower. The suspender displacement and the speed of the tower wake were analyzed. Based on the experimental results, an unsteady aerodynamic model of the suspender was developed, considering the wake stiffness effect, and a wake-induced vibration motion differential equation was derived. The fourth-order Runge-Kutta integration algorithm was used to solve the differential equations. The parameters appearing in the equation were divided into three categories: structural parameters, flow field parameters, and position parameters. The effect of each parameter on the motion characteristics of the suspender was analyzed. The mass ratio parameter plays a significant role in the composition and proportion of the suspender vibration mode. However, the other parameters regulate the vibration amplitude but are insignificant in changing the movement mode. Meanwhile, the large damping ratio of the suspender and the small fluctuation of wind speed in the wake flow can effectively suppress the suspender vibration. This paper presents a method for practical engineering applications for minimizing the amplitude of suspender vibrations.