桁架加劲梁悬索桥后颤振特性节段模型试验研究  

Segmental model tests for post flutter characteristics of truss-stiffening girder suspension bridge

作　　者：张瑞林[1,2] 杨鸿波 刘志文[1,2] 杨健[3] 陈政清[1,2] ZHANG Ruilin;YANG Hongbo;LIU Zhiwen;YANG Jian;CHEN Zhengqing(Hunan Provincial Key Lab for Wind and Bridge Engineering,Hunan University,Changsha 410082,China;College of Civil Engineering,Hunan University,Changsha 410082,China;Guizhou Transportation Planning Survey and Design Academe Co.,Ltd.,Guiyang 550081,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,长沙410082 [2]湖南大学土木工程学院,长沙410082 [3]贵州省交通规划勘察设计研究院股份有限公司,贵阳550081

出　　处：《振动与冲击》2022年第5期1-8,19,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(51778225,51478180)。

摘　　要：以某主跨为1100 m桁架加劲梁悬索桥为工程依托,采用弹性悬挂节段模型风洞试验方法,对桁架梁后颤振特征与机理进行研究。对桁架梁节段模型试验系统的结构动力参数进行测试;在不同风攻角下进行了桁架梁节段模型颤振试验研究;从非线性阻尼角度对桁架梁节段模型极限环振动机理进行探讨。结果表明:在振幅较大时,桁架梁节段模型试验系统存在较为明显的阻尼非线性以及轻微的刚度非线性;在各试验风攻角下,桁架梁节段模型后颤振现象均表现为极限环振动,风攻角对颤振临界风速与振幅随风速增长的斜率均有显著影响;桁架梁节段模型极限环振动具有弯扭耦合特性,并且弯扭耦合程度随振幅增大而增强;对于桁架梁节段模型试验,结构阻尼非线性是后颤振限幅的有利因素,而气动阻尼非线性在不同风攻角下作用效果不同。Here,based on a certain truss-stiffening girder suspension bridge with main span of 1100 m,post flutter characteristics and mechanism of this kind bridge were studied by using wind tunnel test method of elastic suspension segmental model.Firstly,structural dynamic parameters of truss girder segmental model test system were measured.Then,flutter tests of the truss girder were conducted under different wind attack angles.Finally,limit cycle oscillation(LCO)mechanism of the truss girder was discussed from the perspective of nonlinear damping.The results showed that when vibration amplitude is large,the segment model test system has obvious damping nonlinearity and slight stiffness nonlinearity;under each test angle of attack,the post flutter phenomenon of the truss girder reveals a limit cycle oscillation,and wind attack angle significantly affects critical flutter wind speed and amplitude increase slope with wind speed;the limit cycle oscillation of the truss girder has bending-torsion coupled feature,and the coupling degree of bending-torsion enhances with increase in amplitude;for segment model tests,structural damping nonlinearity is a favorable factor for post flutter amplitude-limiting,while aerodynamic damping nonlinearity has different effects under different wind attack angles.

关 键 词：悬索桥 桁架加劲梁 后颤振 非线性阻尼 风洞试验 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]