摘要
大跨度悬索桥在交通荷载和环境激励下,加劲梁产生持续不断的纵向往复运动,这类振动会导致悬索桥上的连接构件如伸缩缝等出现疲劳破坏。抑制这类振动一般是在梁端安装阻尼装置,这类装置不仅能够减少运营状态下的梁端位移,还能减弱地震作用下的梁端位移响应。本文提出采用耐久性能良好的新型电涡流阻尼器(ECD)进行梁端位移控制并对其减振效果进行了评估。首先对某大跨度悬索桥的实测纵向位移数据进行时域和频域分析,通过简化建立了悬索桥纵向振动的单自由度模型(SDOF),并反演了运营状态下的等效外力时程。然后对悬索桥简化SDOF模型在运营状态等效外力时程作用下和地震激励下的响应进行了计算,并评估了ECD在运营低速状态下线性阻尼和地震高速状态下非线性阻尼的减振(震)控制效果,提出了平衡两种状态控制目标的阻尼器参数合理取值范围,为ECD在悬索桥加劲梁纵向位移控制领域的应用提供了一定的理论依据。
Under the action of traffic load and ambient excitation,the main girder of long-span suspension bridge will produce continuous longitudinal movement,which will lead to fatigue failure of connecting members on the suspension bridge,such as expansion joints.To suppress this kind of movement,damping devices are usually installed at the girder ends,which can not only reduce longitudinal displacement under the operation state,but also attenuate the longitudinal response under earthquakes.In this paper,a new type of eddy current damper(ECD)with good durability is proposed to control the girder longitudinal movement and the performance of movement reduction is evaluated.Firstly,the measured longitudinal displacement data of a long-span suspension bridge are analyzed in time domain and frequency domain.Secondly,a simplified equivalent single degree-of-freedom(SDOF)model is established for longitudinal movement analysis of the suspension bridge,and the time history of the equivalent external force in operation state is identified based on the SDOF model and the measured longitudinal displacement data.Thirdly,the response of the SDOF model under the action of external force in operation state is calculated and the corresponding linear damping control performance of ECD at low speed is evaluated.Fourthly,the seismic response of the SDOF model is calculated and the corresponding nonlinear damping control performance of ECD at high speed is evaluated.Lastly,a reasonable range of damper parameters for balancing control targets of two states of operation state and seismic state is proposed.It provides a theoretical basis for the application of ECD in longitudinal movement reduction of suspension bridge girders.
作者
梁龙腾
封周权
陈政清
牛华伟
华旭刚
LIANG Longteng;FENG Zhouquan;CHEN Zhengqing;NIU Huawei;HUA Xugang(Key Iaboratory of Wind and Bidge Engineering of Hunan Prorine,Hunan Univesty,Changsbha 410082,Chin;State Key ILabonatory of Adranced Design and Manudacturing for Vehiele Body,Hiunan Univerity,Changha 410082,China)
出处
《地震工程与工程振动》
CSCD
北大核心
2020年第4期118-127,共10页
Earthquake Engineering and Engineering Dynamics
基金
国家自然科学基金项目(51708203)
湖南大学汽车车身先进设计制造国家重点实验室自主研究课题(71865006,71865004)
国家重点研发计划“先进轨道交通”重点专项项目(2018YFB1201703)。
关键词
大跨度悬索桥
纵向振动
电涡流阻尼器
振动控制
阻尼器参数
long span suspension bridge
longitudinal vibration
eddy current damper
vibration control
damper parameters
