间距和风攻角对分离双扁平箱梁涡振特性的影响

发布时间：2018-01-03 06:03

本文关键词：间距和风攻角对分离双扁平箱梁涡振特性的影响　出处：《石家庄铁道大学》2016年硕士论文　论文类型：学位论文

【摘要】：为了满足日益增长的交通量需求,现代跨江跨海大桥主梁常设计为彼此分离且相互平行的双幅箱梁。由于两箱之间的气动干扰作用,分离双箱梁的涡振特性不同于单箱梁的涡振特性。在某些情况下,分离双箱梁的涡振振幅可能会更大,发生涡振的概率可能会更高。为了避免分离双箱梁桥发生大振幅的涡激振动,十分有必要对其涡振特性展开深入研究。本文以国内某座分离双扁平箱梁桥为背景,开展了一系列节段模型测压测振风洞试验。首先研究了不同风攻角下单幅扁平箱梁的涡振特性;然后在+5°风攻角开展了16个不同间距下分离双扁平箱梁的涡振特性研究;最后根据+5°风攻角的试验结果选取了4个典型间距,并在典型间距下开展了不同风攻角下分离双扁平箱梁的涡振特性研究。全文主要包括以下内容:(1)研究了不同风攻角下单幅扁平箱梁的涡振特性。研究发现:单幅扁平箱梁在负风攻角下的涡振性能优于正风攻角下的涡振性能。正风攻角条件下,涡振性能随着风攻角的增大逐渐变差,涡振振幅更大,涡振锁定区间更长。(2)在+5°风攻角下研究了间距对分离双扁平箱梁涡振特性的影响。研究发现:+5°风攻角下,间距对上游箱梁与下游箱梁涡振特性的影响均可大致分为4个区间。(3)在4个典型间距下研究了风攻角对分离双扁平箱梁涡振特性的影响。研究发现:在单幅扁平箱梁发生涡振的几个风攻角(+5°、+4°和+3°风攻角)下,分离双扁平箱梁的涡振特性表现出了大体相似的变化规律,这表明在这些风攻角下,间距对分离双扁平箱梁涡振特性的影响均可大致分为4个区间,只不过这些区间的划分略有不同。在单幅扁平箱梁没有发生涡振的一些风攻角(如+2°风攻角)下,分离双扁平箱梁在某些特定的间距发生了明显的涡振现象,这表明,与单幅扁平箱梁相比,分离双扁平箱梁发生涡振的概率更高。
[Abstract]:In order to meet the increasing demand of traffic volume, the main girder of modern cross-river bridge is usually designed as a two-piece box girder which is separated from each other and parallel to each other, because of the aerodynamic interference between the two boxes. The vortex vibration characteristic of separated double box girder is different from that of single box girder. In some cases, the amplitude of vortex vibration of separated double box girder may be larger. The probability of vortex-induced vibration may be higher. In order to avoid large amplitude vortex-induced vibration of separated double-box-girder bridge. It is very necessary to carry out a thorough study on the vortex vibration characteristics of the bridge. This paper takes a separated double-flat box girder bridge as the background. A series of wind tunnel tests of segmental model pressure and vibration measurement are carried out. Firstly, the vortex vibration characteristics of a single flat box girder with different angles of attack are studied. Then the vortex vibration characteristics of the separated double flat box girder with 16 different spacing are studied at 5 掳wind attack angle. Finally, four typical distances are selected according to the test results of 5 掳wind attack angle. The vortex vibration characteristics of separated double flat box girders with different wind attack angles are studied under typical spacing. The main contents of this paper are as follows: 1). The vortex vibration characteristics of a single flat box girder at different angles of attack are studied. It is found that the vortex vibration performance of a single flat box girder is better than that of a single flat box girder at a negative wind attack angle. The vortex vibration performance becomes worse with the increase of wind attack angle, and the amplitude of vortex vibration becomes larger. The effect of spacing on vortex vibration characteristics of separated double flat box girder is studied at 5 掳wind attack angle. The results show that: 5 掳wind attack angle. The effect of spacing on vortex vibration characteristics of upstream box girder and downstream box girder can be roughly divided into 4 sections. The effect of wind attack angle on vortex vibration characteristics of separated double flat box girder is studied under four typical distances. It is found that several wind attack angles (5 掳) occur in a single flat box girder. Under 4 掳and 3 掳wind attack angles, the vortex-vibration characteristics of the separated double-flat box girders show a similar variation law, which indicates that under these wind attack angles. The effect of spacing on vortex vibration characteristics of separated double flat box girder can be roughly divided into 4 regions. However, the division of these sections is slightly different. Some wind attack angles (such as 2 掳wind attack angle) without vortex vibration are found in single flat box girder. The phenomenon of vortex vibration of separated double flat box girder is obvious in some special spacing, which shows that the probability of vortex vibration of separated double flat box girder is higher than that of single flat box girder.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U441.3

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