Study of central buckle effects on flutter of long-span suspension bridges
Study of central buckle effects on flutter of long-span suspension bridges
复制标题
大跨悬索桥颤振中心扣效应研究
DOI：
10.12989/was.2020.31.5.403
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发表时间：
2020-11
影响因子：
1.6
通讯作者：
C. S. Cai
中科院分区：
文献类型：
--
作者：
Yan Han;Kai Li;C. S. Cai
为了研究中心扣件对大跨度悬索桥动力特性和颤振稳定性的影响，研究了艾寨大桥主缆与跨中附近主梁的4种不同连接方案。基于风洞试验得到的颤振导数，采用非线性最小二乘拟合法得到了自激振力的时间域公式，实现了颤振分析。随后，研究了中心屈曲对该桥颤振临界速度、颤振频率和三维颤振状态的影响。结果表明，中心屈曲能显着提高桥梁纵向浮动振型的频率，对非对称横向弯曲振型和非对称扭转振型的频率的影响大于对称振型的影响。由于艾寨大桥的颤振模式实质上是对称扭转振型和对称竖向振型的耦合，因此中心屈曲对颤振临界速度的影响较小。然而，中心屈曲对桥梁的颤振模式和三维颤振状态有一定的影响。此外，还发现当结构阻尼值为0或很低时，桥梁颤振状态会出现复杂拍振现象(称为间歇性颤振现象)。
To investigate the effects of central buckles on the dynamic behavior and flutter stability of long-span suspension bridges, four different connection options between the main cable and the girder near the mid-span position of the Aizhai Bridge were studied. Based on the flutter derivatives obtained from wind tunnel tests, formulations of self-excited forces in the time domain were obtained using a nonlinear least square fitting method and a time-domain flutter analysis was realized. Subsequently, the influences of the central buckles on the critical flutter velocity, flutter frequency, and three-dimensional flutter states of the bridge were investigated. The results show that the central buckles can significantly increase the frequency of the longitudinal floating mode of the bridge and have greater influence on the frequencies of the asymmetric lateral bending mode and asymmetric torsion mode than on that of the symmetric ones. As such, the central buckles have small impact on the critical flutter velocity due to that the flutter mode of the Aizhai Bridge was essentially the symmetric torsion mode coupled with the symmetric vertical mode. However, the central buckles have certain impact on the flutter mode and the three-dimensional flutter states of the bridge. In addition, it is found that the phenomenon of complex beat vibrations (called intermittent flutter phenomenon) appeared in the flutter state of the bridge when the structural damping is 0 or very low.