积雪对桥梁空气动力的影响研究

发布时间：2018-03-06 05:18

  本文选题：主梁　切入点：风致雪漂移　出处：《西南交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：风致雪漂移现象已经成为目前研究热点。本文回顾了风致雪漂移运动的研究现状及其分析过程中存在的问题。采用FLUENT数值模拟软件分析桥面积雪的二维分布,并通过风洞试验重点研究积雪对主梁颤振导数、涡激振动性能的影响,具体内容以及结果如下：1、以截面为流线形的钢箱梁斜拉桥为例,使用通用软件Gambit建模以及划分网格,通过FLUENT软件数值模拟得到桥面积雪分布形状。结果表明：积雪的沉积侵蚀与壁面摩擦速度有紧密的联系,桥面背风侧积雪侵蚀量明显比迎风侧侵蚀量小,在尾流处侵蚀量最小。2、通过风洞试验研究积雪对主梁三分力系数的影响：由于积雪作用,主梁升力系数与扭矩系数的曲线的斜率变大同时增幅在40%左右；阻力系数增大15%左右,且三分力系数变化趋势基本不变。3、通过试验分析积雪对主梁涡激振动性能的影响。试验发现：由于积雪作用,主梁在+3。时的竖向涡激振动消失且三个风速下的积雪的影响基本一致。4、经风洞试验研究后认为积雪对主梁颤振导数有一定的影响。由于积雪作用,由竖向运动位移引起的气动惯性和气动刚度对自激升力和扭矩的贡献由负变正；由扭转运动位移引起的气动惯性和气动刚度对自激扭矩的贡献减小,且风速20m/s时影响相对较大；折减风速增大到2左右时,由扭转运动速度引起的气动阻尼对自激升力的贡献变为负。
[Abstract]:The wind-induced snow drift phenomenon has become the focus of research. This paper reviews the present situation and analysis of drift motion of wind-induced snow in question. By using FLUENT numerical simulation software to analyze the two-dimensional distribution of snow on the bridge, and through the research on the snow wind tunnel tests of flutter derivatives, vortex induced vibration performance influence, concrete contents and results are as follows: 1, to streamline the cross section of steel box girder cable-stayed bridge as an example, using Gambit software modeling and meshing, through FLUENT software numerical simulation of bridge snow distribution. The results showed that: there are closely related to erosion and deposition of snow wall surface friction velocity, deck erosion than the leeward side of the snow the windward side erosion, erosion of the minimum amount of.2 flow in the tail, through snow wind tunnel test on influence on beam three component coefficient: due to snow, Lord Liang Sheng The slope coefficient and torque coefficient curve becomes larger and an increase of about 40%; the resistance coefficient increased about 15%, and the three component coefficient trend unchanged.3, through the experimental analysis of influence of snow on the main beam of vortex induced vibration performance. Experiment results showed that: because of the snow, the effect of vertical vortex induced vibration disappeared when +3. beam and the three wind under the snow is consistent with the.4, the wind tunnel tests that snow has certain effects on the flutter derivatives. Because of the snow, the contribution caused by the vertical displacement of pneumatic inertia and aerodynamic stiffness of self-excited force and torque rise from negative to positive; caused by torsional displacement pneumatic inertia and aerodynamic stiffness on the self-excited torque contribution decreases, and the speed of 20m/s when the impact is relatively large; the reduced velocity increases to about 2, caused by torsional velocity of aerodynamic damping of self-excited rise The contribution of the force becomes negative.

【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3
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本文编号：1573484