斜拉索风雨激振中拉索和水线之间的耦合运动  

COUPLED MOTION BETWEEN STAY CABLES AND RIVULETS IN RAIN-WIND INDUCED VIBRATION

作　　者：李寿英[1] 陈政清[1] 顾明[2] 

机构地区：[1]湖南大学风工程试验研究中心,长沙410082 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《振动与冲击》2008年第10期1-5,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金资助项目(50708035);中国博士后科学基金资助项目(20060400873)

摘　　要：斜拉索风雨激振严重影响到斜拉桥的安全运营,但其机理至今仍无定论。如何假定水线与拉索表面之间的作用力是建立风雨激振理论模型的难点之一。假定水线与拉索表面之间作用力包括库仑阻尼力和线性阻尼力,推导了拉索和水线的运动微分方程,建立了三维节段拉索风雨激振理论分析模型。采用数值方法对拉索和水线运动微分方程进行求解,得到了拉索和水线的运动规律。结果表明:拉索振动具有"限速"、"限幅"的特征,并能够采用拉索竖向气动力的突降进行解释;水线在拉索表面的平衡主要是气动力和重力之间的平衡,拉索运动产生的附加惯性力为水线往复运动提供能量,而库仑阻尼力和线性阻尼力则消耗能量阻止水线从拉索表面脱落。Rain-wind induced vibration of stay cable,whose mechanism is still unclear by now,severely affects the safety of cable-stayed bridges.The action between rivulet and cable surface is one of the difficulties in establishing theoretical models of rain-wind induced vibration.Here,assuming the action between rivulet and cable surface to be coulomb damping force and linear force,motion equations of cable and rivulet are simultaneously derived.Runge-Kutta method is used to solve the equation set,and the responses of cable and rivulet are obtained.Results show that the motion of cable has the characteristics of 'velocity restricted' and 'amplitude restricted',and it could be explained by the sudden dive of aerodynamic force.Whether the rivulet steadily exists on the upper surface of stay cable or not depends on the balance of aerodynamic force and gravity.Additional inertia force due to the motion of cable provides energy for the motion of the rivulet,and damping force between rivulet and cable surface dissipates energy to stabilize the rivulet motion.

关 键 词：风雨激振 斜拉索 水线 耦合运动 机理 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]