阻尼器对悬索桥双吊索减振效果的理论研究  

THEORETICAL INVESTIGATION FOR THE EFFECTIVENESS OF THE DAMPERS INSTALLED BETWEEN THE HANGERS OF SUSPENSION BRIDGES

作　　者：李寿英[1] 曾庆宇[1] 王世峰[1] 邹国栋 陈政清[1] 

机构地区：[1]湖南大学风工程与桥梁工程湖南省重点实验室,湖南长沙410082 [2]湖南兵器轻武器研究所有限责任公司,湖南413000

出　　处：《工程力学》2018年第3期186-192,226,共8页Engineering Mechanics

基　　金：国家自然科学基金项目(51578234);国家重点基础研究发展计划项目(2015CB057701;2015CB057702)

摘　　要：多座悬索桥吊索发生大幅振动,需提出有效措施对其进行控制。采用理论分析方法,研究阻尼器对悬索桥吊索的减振效果。首先,考虑双索股吊索的面内振动,忽略吊索的弯曲刚度影响,推导了双索股之间安装阻尼器时的运动微分方程;然后,采用有限差分法,对吊索-阻尼器结构体系的运动微分方程进行数值求解,得到了该结构体系的振动频率、振型和阻尼比;以西堠门大桥的典型吊索为工程背景,研究了索股之间安装单个和多个阻尼器的动力特性变化规律。研究结果表明:在索股间安装阻尼器,不能提高索股同向振动模态的阻尼比,减振效果不佳;在吊索之间等间距安装多个阻尼器,且确保阻尼器阻尼系数较大时,可使两根索股成为整体,缩短单根索股的有效长度,提高单根索股的刚度,对抑制风致振动有利。不建议采取该方法进行吊索振动控制。从西堠门大桥的振动控制经验来看,在索股之间安装刚性分隔架能起到更好的控制效果。The large amplitude vibrations of hangers on several suspension bridges all over the world were observed in recent years. Some effective countermeasures should be adopted to mitigate this type of vibration. In this paper, the effectiveness of the dampers to the vibrations of bangers is investigated by using theoretical analyses. First, the equations governing the in-plane motion of a twin-hanger-damper system are derived by neglecting the stiffness of hangers. Second, the finite difference method （FDM） is utilized to numerically solve the equations, and the natural frequency, mode shape and damping ratio are obtained. Third, taking a hanger on Xihoumen Bridge as engineering background, the effectiveness of dampers to mitigate the hanger＇s vibration is carefully investigated. The results show that the damping ratio of the synchronous mode of the two strands does not increase by installing dampers between the two strands. However, the stiffness for single strand could be enhanced by uniformly installing dampers between the two strands because the effective length of the single strand becomes shorter. It is benefit for mitigating wind induced vibration of hangers. The authors suggest that rigid spacers are suitable for reducing the relative oscillation between the strands.

关 键 词：悬索桥吊索 振动控制 阻尼器 理论分析 有限差分法 

分 类 号：U441.3[建筑科学—桥梁与隧道工程] U448.25[交通运输工程—道路与铁道工程]