分体箱梁中央隔涡板涡激振动抑制机理研究

Mechanism of the vortex-induced vibration control for twin-box girders with central baffle plates

借助风洞试验和计算流体力学对分体钢箱梁的涡激振动性能及中央隔涡板的抑振效果与机理开展研究,对比不同形式(水平隔涡板、一道竖向隔涡板、两道竖向隔涡板)和尺寸中央隔涡板的抑振效果,并根据流迹与速度云图对不同形式中央隔涡板的抑振机理进行分析。结果表明:开槽顶部水平隔涡板能够阻碍开槽处的气体对流,降低开槽内部及断面周围气流速度,增加旋涡移动和脱落难度,从而在一定程度上抑制涡激振动,抑振效果随隔涡板宽度增大而增加;开槽内部竖向隔涡板能够将旋涡稳定在隔板分隔出的几个小区域内,避免产生稳定的旋涡脱落,进而有效抑制涡激振动,设置两道半高竖向隔涡板比设置一道全高竖向隔涡板效果更好,但需对两板间距进行优化。

The vortex-induced vibration(VIV)performance of twin-box girders and the mechanism of the vortex-induced vibration control by central baffle plates were studied through wind tunnel tests and computational fluid dynamics analysis.The effectiveness of different types(horizontal,one vertical,and two vertical plates)and sizes of central baffle plates was compared,and the corresponding VIV control mechanisms were discussed based on the streamlines and vorticity magnitude contours.The results demonstrate that horizontal plates impede airflow,reduce wind velocity near the section,increase vortex shedding difficulty,and thus control the VIV.Control effectiveness increases with the plate width.Meanwhile,vertical plates stabilize vortices in small areas,prevent vortex shedding,and effectively control the VIV.The control effect of two half-height vertical plates is superior to that of one full-height vertical plate,however,it needs the optimization of the distance between the two plates.