大跨径悬带桥颤振特性研究  

Flutter Characteristics of Long-span Stress-ribbon Bridges

作　　者：华旭刚[1] 王圣淇 唐煜 陈政清[1] HUA Xu-gang;WANG Sheng-qi;TANG Yu;CHEN Zheng-qing(Key Laboratory of Wind and Bridge Engineering of Hunan Province,Hunan University,Changsha 410082,Hunan,China)

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

出　　处：《中国公路学报》2021年第1期57-65,共9页China Journal of Highway and Transport

基　　金：国家自然科学基金杰出青年基金项目(52025082);国家自然科学基金项目(51808470)。

摘　　要：借助一种三维颤振分析方法,分析一座主跨618 m悬带桥的三维颤振性能,并与相同跨径的悬索桥进行对比,进一步探讨悬带桥的多模态参与效应、侧向自激力效应及节段模型试验的模态选取等问题;同时还对悬带桥进行多种组合下的两模态二维颤振分析及节段模型风洞试验。研究结果表明:与悬索桥的扭转模态颤振驱动机制不同,悬带桥的颤振由侧向-扭转耦合模态分支驱动,具有更低的颤振临界风速;悬带桥的颤振形态表现为侧向、竖向和扭转方向耦合振动,侧向自激力对颤振临界风速的影响较小;侧弯-扭转耦合模态及竖弯模态的模态组合具有最低的颤振临界风速,二维颤振分析结果与三维颤振分析结果基本一致,说明其多模态参与效应不明显,由此可见三维颤振分析及节段模型中模态合理选取的重要性。研究结果可为其他新颖体系大跨径桥梁的颤振研究提供参考。By means of a three-dimensional flutter analysis method, the three-dimensional flutter characteristics of a 618 m-long( main span) stress-ribbon bridge( SRB) were analyzed,and were compared with those of the traditional suspension bridge( TSB) with the same span length. The multimodal participation effect,the lateral-motion induced self-excited forces and the mode selection problem of sectional model flutter test are discussed. Both two-dimensional flutter analysis and section model test are carried out by using different combinations of two modes for SRB. In contrast to the torsional-modedriven flutter of TSB,the flutter of SRB is originated from the natural lateral-torsional coupled mode of SRB,and has a lower flutter critical velocity. The characteristic motion at flutter onset is dominated in the lateral,vertical and torsional directions,and the lateral self-excited forces have minor effect on critical flutter speed of SRB. It is shown that the combination of the lateral-torsional coupled mode and the vertical mode gives the lowest critical flutter speed. Moreover,the two-dimensional results are in good agreement with the 3 D flutter analysis results,indicating that the multi-modal participation effect of SRB is not obvious. This study shows the importance of 3 D flutter analysis and mode selection method in sectional model,and can also provide reference for the flutter research of other new-type long-span bridges.

关 键 词：桥梁工程 颤振 颤振分析 悬带桥 悬索桥 侧向自激力 节段模型试验 

分 类 号：U44[建筑科学—桥梁与隧道工程]