AERODYNAMIC COUPLING EFFECTS ON FLUTTER AND BUFFETING OF BRIDGES
AERODYNAMIC COUPLING EFFECTS ON FLUTTER AND BUFFETING OF BRIDGES
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DOI：
10.1061/(asce)0733-9399(2000)126:1(17
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
Xinzhong Chen;M. Matsumoto;A. Kareem
中科院分区：
文献类型：
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作者：
Xinzhong Chen;M. Matsumoto;A. Kareem
研究了不同振型间气动耦合对大跨度桥梁颤振和抖振响应的影响。通过引入非定常自激气动力的有理函数近似，将广义模态坐标下的运动方程转化为与频率无关的状态空间格式。通过求解复特征值问题，确定了给定风速下的频率、阻尼比和复模态振型以及临界颤振条件。这种方法的一个显著特点是，确定颤振条件的迭代解是不必要的，因为运动方程是独立的频率。利用广义气动力所做的功或沿桥轴的自激力所做的功来检验每个颤振运动周期的能量增加。因此，它们对气动阻尼的贡献可以清楚地确定。研究了多模态颤振的产生机理和颤振导数的作用。最后，讨论了自激力对颤振响应的耦合效应。
The effects of aerodynamic coupling among modes of vibration on the flutter and buffeting re- sponse of long-span bridges are investigated. By introducing the unsteady, self-excited aerodynamic forces in terms of rational function approximations, the equations of motion in generalized modal coordinates are transformed into a frequency-independent state-space format. The frequencies, damping ratios, and complex mode shapes at a prescribed wind velocity, and the critical flutter conditions, are identified by solving a complex eigenvalue problem. A significant feature of this approach is that an iterative solution for determining the flutter conditions is not necessary, because the equations of motion are independent of frequency. The energy increase in each flutter motion cycle is examined using the work done by the generalized aerodynamic forces or by the self-excited forces along the bridge axis. Accordingly, their contribution to the aerodynamic damping can be clearly identified. The multimode flutter generation mechanism and the roles of flutter derivatives are investigated. Finally, the coupling effects on the buffeting response due to self-excited forces are also discussed.