桥下净空对大跨度桥梁颤振稳定性的影响研究

Study on Influence of Bridge Clearance on Flutter Stability of Large-span Bridge

为研究桥下净空对桥梁颤振稳定性的影响,基于CFD数值仿真技术,识别了在多种桥下净空工况下大带东桥的颤振导数和颤振临界风速。研究表明:每个工况下的气动导数曲线趋势与试验结果基本吻合,没有随着桥下净空的改变而出现大的波动,边界对耦合气动负阻尼和扭转自身正阻尼影响有限;在桥梁抗风设计和抗风试验值中,可不考虑桥下净空振稳定性的影响。

In order to study the influence of the bridge clearance on the flutter stability of the bridge, the CFD numerical simulation technique is used to identify the flutter derivative and the flutter critical wind speed under of Dadaidong Bridge under the a variety of bridge clearance conditions. The study results show that the trend of aerodynamic derivative curve in each condition is basically consistent with the experimental result,and there is no large fluctuation with the change of bridge clearance. The influence of the boundary on the coupling of the aerodynamic negative damping and the reversal positive damping itself is limited. The influence of the bridge clearance on the flutter stability of the bridge cannot be considered in the wind resistance design and wind resistance test value of bridge.