Experimental study on flutter control of active flaps nearby wind fairing sides of streamlined box girder
Zhao Lin1,2,3 Wang Zilong1 Chen Hanlin1 Li Ke4,5 Ge Yaojun1,2
1. State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China;
2. Key Laboratory of Transport Industry of Wind Resistant Technology for Bridge Structures, Tongji University, Shanghai 200092, China;
3. State Key Laboratory of Mountain Bridge and Tunnel Engineering, Chongqing Jiaotong University, Chongqing 400074, China;
4. School of Civil Engineering, Chongqing University, Chongqing 400045, China; 5. Key Laboratory of New Technology for
Construction of Cities in Mountain Area of the Ministry of Education, Chongqing University, Chongqing 400045, China
With the development of bridge engineering, it is hard for traditional passive aerodynamic measures to meet the wind resistance requirements due to the continuous expansion of bridge spans, so that much attention has been paid to active aerodynamic measures. To resolve this issue and explore the potential capability of the active measure, a new bridge flutter control method based on active flaps was proposed, and a set of main girder-active flaps scaled models were designed and fabricated for verifying their control effects. A pair of horizontal flaps are set on both sides of the box girder, the movement behavior of the main girder is measured by sensors, so that the counter-movement of the box girder may be implemented by applying a specific amplification factor (gain coefficient) relative to the girder’s vibration amplitude. Furthermore, the movement of the flaps may change the flow field around the girder, and the flutter stability of the girder may be improved. Based on these steps, a whole closed-loop feedback control system was built. Under uniform flow conditions, by adjusting the gain coefficient in the motion function of the flaps and the combination of the phase difference between the aerodynamic flaps and the box girder, the control law of the flutter critical wind speed can be revealed. Based on the study, it is found that both the phase difference combination and gain coefficient of both sides of the aerodynamic flap may significantly affect the flutter performance of the main girder-flaps system. When the phase difference of windward flap and the girder maintain is kept to be 180°～360° and the phase difference of the leeward side flap and the girder is kept to be 0°～180°, the flutter performance of the system can be improved greatly. When the gain coefficient is between 1 and 9, a very small gain coefficient only has a limited improvement on the system flutter performance, but a too large gain coefficient may deteriorate the system’s flutter performance. When the gain coefficient lies in the range of 3～4, the optimal control effect can be achieved.
赵林 王子龙 陈翰林 李珂 葛耀君. 流线箱梁风嘴侧主动气动翼板的颤振控制试验研究[J]. 土木工程学报, 2022, 55(6): 36-46.
Zhao Lin Wang Zilong Chen Hanlin Li Ke Ge Yaojun. Experimental study on flutter control of active flaps nearby wind fairing sides of streamlined box girder. 土木工程学报, 2022, 55(6): 36-46.
