基于CFD流线型桥梁断面二维涡激振动分析

2D ortex-induced vibration analysis of streamline bridge cross-section based on CFD

为研究长山大桥流线型箱梁二维涡激振动特性,基于数值风洞的方法,采用Gambit建立桥梁截面流场并划分网格,将桥梁截面涡激振动模型简化为竖向单自由度弹簧体系并求解.研究结果表明:流线型箱梁的漩涡产生于桥梁截面入风端,经桥梁上截面,逐渐移至截面尾部,脱落于截面尾部尾流中;易引起涡激振动的折算风速为8~20.研究结论可为预防桥梁涡激共振和涡激振动应急处理提供参考.

In order to study the two-dimensional vortex-induced vibration of streamlined box girder of Changshan Bridge,based on the method of numerical wind tunnel,Gambit was used to establish the flow field of bridge section and divide the grid.The vortex-induced vibration model of bridge section was simplified to a vertical single-degree-of-freedom spring system and solved.The results of study show that the vortex of streamlined box girder is generated at the wind inlet of the bridge section,and gradually moves to the tail of the section through the upper section of the bridge,and falls off in the tail flow of the section.The converted wind speed that is easy to cause vortex-induced vibration is 8~20.The research conclusions provide reference for the prevention of vortex-induced resonance and vortex-induced vibration emergency treatment of bridges.