大跨度悬索桥钢箱加劲梁中央开槽的颤振控制机理  

Flutter Mitigation of Long Span Suspension Bridges with Central Slotted Box Girders

作　　者：邹小洁[1] 杨詠昕[2] 葛耀君[2] 

机构地区：[1]上海市政工程设计研究院,上海200092 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《力学季刊》2007年第2期187-194,共8页Chinese Quarterly of Mechanics

基　　金：国家自然科学基金(50278069)

摘　　要：针对近流线型的闭口钢箱梁这种大跨悬索桥常用的加劲梁断面形式,采用风洞试验与理论分析相结合的方法研究不同宽度中央开槽的颤振控制作用与颤振控制机理。通过对原型断面和5种槽宽开槽断面(开槽宽度分别为原型断面宽度的20%、40%、60%、80%和100%)的试验研究表明,适当宽度的中央开槽可以较大幅度的提高颤振临界风速,但槽宽并非越宽越好,而是存在一个“最优槽宽”。采用二维三自由度耦合颤振分析方法从气动阻尼和颤振形态矢量两方面对中央开槽的颤振控制机理进行理论研究,结果表明,适当宽度的中央开槽可以改善气动阻尼的形成和发展规律,并提高颤振发生时竖弯自由度的参与程度和扭弯耦合程度,从而增强结构的颤振稳定性能。To find out the effect of central slotting on the aerodynamic stability of long-span suspension bridges with closed box girders, a series of wind tunnel tests and theoretical analysis were carried out by adjusting the width of central slotting. The results of tests on the basic section and slotted sections with five different slot width show that central slotting with appropriate slot width can improve the critical flutter speed, but the relationship between flutter performance and slot width is not mono increasing, there exists an＂optimum slot width＂. Then the theoretical research on the aerodynamic damping and flutter modality was carried out by 2d3DOF method. The results indicate that central slotting with appropriate slot width improves the formation and evolution of aerodynamic damping and increases the participation level of vertical bending mode of vibration and the coupling degree of torsional and vertical bending modes, so enhances the aerodynamic stability of structures.

关 键 词：悬索桥 钢箱加劲梁 中央开槽 颤振控制 耦合颤振 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]