Π型叠合梁斜拉桥涡激振动性能及气动措施研究  

Vortex-induced vibration performance and aerodynamic countermeasures of Π-shaped composite girder of a cable-stayed bridge

作　　者：蒋尚君 朱金 鲁胜龙 李永乐[1] 康锐 JIANG Shang-jun;ZHU Jin;LU Sheng-long;LI Yong-le;KANG Rui(Department of Bridge Engineering,School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院桥梁工程系,四川成都610031

出　　处：《振动工程学报》2024年第5期830-837,共8页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(51908472);中国博士后科学基金资助项目(2019TQ0271,2019M663554);四川省科学技术厅科技计划项目(2020YJ080)。

摘　　要：型叠合梁为气动钝体结构,容易发生气动失稳。本文以一座Π型截面叠合梁斜拉桥作为工程背景,采用风洞节段模型试验与计算流体动力学(CFD)方法,对主梁的涡激振动性能及相应的气动抑振措施展开了研究。在风洞节段模型试验中获得涡激振动风速区间,讨论了不同气动措施的抑振效果,运用计算流体动力学(CFD)方法对主梁涡振发生机理及气动措施抑振机理进行了初步研究。结果表明:在原始断面下,由于尾迹区旋涡的周期性脱落以及主梁上、下表面旋涡演变的相互作用,导致了涡激振动发生。在采取三种不同抑振措施后,除采用上L型导流板断面在+3°风攻角下发生扭转涡振外,其余优化断面均能使得来流平稳地通过,从而抑制涡振发生。本研究可对Π型叠合梁断面的斜拉桥抗风设计提供一定参考。shaped composite deck is an elastic bluff body,which is susceptible to aerodynamic instability.In the present study,a cable-stayed bridge with a Π-shaped composite deck is taken as the research object,and the vortex-induced vibration(VIV) and the aerodynamic countermeasures are investigated by using the small-scale wind tunnel tests and computational fluid dynamics(CFD) method.The wind speed range of the VIV for the Π-shaped composite deck is determined via the wind tunnel test.After that,several VIV mitigation measures are investigated.The computational fluid dynamics(CFD) method is used to study the mechanism of VIV and vibration suppression by aerodynamic measures.The results indicate that the VIV in the original section is caused by the interaction of the periodic shedding of the vortex in the wake area and the vortex evolution on the upper and lower surfaces of the girder;After adopting three different aerodynamic measures,the flow can pass through the section more smoothly,so as to mitigate the VIV effectively,except for the upper inverted L-shaped guide plate at the wind attack angle of +3°.This study can offer guidance on the wind-resistant design of a cable-stayed bridge with a Π-shaped composite deck.

关 键 词：涡激振动 抑振措施 叠合梁 风洞试验 计算流体动力学(CFD) 

分 类 号：O32[理学—一般力学与力学基础] U448.27[理学—力学]