三维新月形变截面覆冰斜拉索气动力特性研究

发布时间：2018-01-22 08:15

本文关键词： 变截面覆冰斜拉索气动力参数驰振　出处：《建筑科学与工程学报》2017年03期 　论文类型：期刊论文

【摘要】：为研究变截面覆冰对斜拉索气动力特性的影响,应用FLUENT中的SST k-ω模型对三维新月形变截面覆冰斜拉索绕流场进行数值模拟;将变截面覆冰斜拉索模型划分为6个节段,分别监测不同覆冰厚度节段的气动力,得到全攻角下各节段以及全索的阻力系数和升力系数;基于Den Hartog机制,获得驰振力系数,进而研究变截面覆冰斜拉索的驰振稳定性。结果表明:变截面覆冰形态对斜拉索的流场分布影响较大,其绕流场具有明显的三维流动特性;由于覆冰厚度的变化,变截面覆冰斜拉索各节段表现出不同的气动力特性和驰振稳定性;经过三维模拟计算,变截面覆冰斜拉索各节段及全索的部分驰振力系数小于0,拉索具有发生覆冰驰振的可能性,变截面覆冰对斜拉索的气动力特性影响较大。
[Abstract]:In order to study the effect of ice-covered cable with variable cross-section on the aerodynamic characteristics of cable-stayed cables, the SST k- 蠅 model in FLUENT is used to simulate the flow field around the frozen cable-stayed cable with three dimensional crescent deformation section. The model is divided into six segments, and the aerodynamic forces of the segments with different icing thickness are monitored, and the drag coefficient and lift coefficient of each segment and the whole cable at full attack angle are obtained. Based on the mechanism of Den Hartog, the coefficient of galloping force is obtained, and the galloping stability of ice-covered cables with variable cross-section is studied. The results show that the shape of icing with variable cross-section has a great influence on the distribution of flow field of the cables. The flow field around it has obvious three-dimensional flow characteristics. Because of the change of ice thickness, the different aerodynamic characteristics and galloping stability of each segment of the frozen stay cable with variable cross-section are shown. Through 3D simulation calculation, the coefficient of partial galloping force of each segment and the whole cable is less than 0, the possibility of ice-covered vibration of cable is obtained, and the influence of icing on aerodynamic characteristics of stay cable is great.
【作者单位】：武汉理工大学道路桥梁与结构工程湖北省重点实验室;
【基金】：国家自然科学基金项目(51408452) 道路桥梁与结构工程湖北省重点实验室开放基金项目(DQJJ201509)
【分类号】：U448.27
【正文快照】： 0引言在寒冷冬季,大跨斜拉桥拉索表面容易被包裹上冰层,覆冰后拉索截面发生改变。在斜拉索偏心覆冰后,其气动外形不再稳定,在特定风速和风攻角条件下容易发生驰振。驰振是一种低频率、大振幅的自激振动,大振幅的驰振将威胁到拉索结构的安全,因此,有必要对覆冰拉索的驰振稳定性

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