自锚式悬索桥磁流变阻尼器减震控制研究

为了减小自锚式悬索桥的地震响应,基于桥梁结构地震动力方程及磁流变阻尼器力学模型,建立桥梁结构—磁流变阻尼器减震系统并将其程序化,对某主跨350 m的独塔自锚式悬索桥进行减震控制研究,讨论了磁流变阻尼器输入电流、数目及安装位置对减震效果的影响。研究结果表明:采用磁流变阻尼器能够有效地减小自锚式悬索桥的纵向地震响应;随安装在塔梁之间顺桥向的磁流变阻尼器输入电流的增大及数目的增加,塔顶和主梁的纵向位移逐渐减小,结构的内力响应也得到有效控制;将全部磁流变阻尼器安装在塔梁之间顺桥向时减震效果最佳。

Study on the seismic response control of self-anchored suspension bridges with MR dampers

To mitigate the seismic response of self-anchored suspension bridges,based on the earthquake dynamic equation of bridge structure and a mechanical model of magnetic-rheological(MR) damper,a system composed of the bridge structure and the MR damper is established,and a computer program is developed and employed for studying the seismic response control of a single-tower self-anchored suspension bridge with a main span of 350m.The effect of seismic response control via variable current,number and setting position of MR dampers is discussed.The study indicates that MR dampers can effectively reduce the longitudinal seismic response of self-anchored suspension bridges.With increase in the input current and the number of MR dampers between the main tower and the main girder in the longitudinal bridge direction,the longitudinal displacements of the tower top and the main girder decrease,and the internal force response of the structure can effectively be controlled.The best effect of seismic response control would be reached when all MR dampers are placed between the main tower and the main girder in the longitudinal bridge direction.