方形截面桥塔的驰振机理及气动制振措施研究

发布时间：2018-03-09 17:14

本文选题：倒角　切入点：桥塔　出处：《西南交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来桥梁的跨径开始不断增大,桥梁主塔高度也随之不断的拔升,而塔柱一般为钝体截面,抗风性能较差,在自立状态下的风致振动问题显得尤为突出。本文以某倒角方形截面桥塔为工程实验背景,通过其在裸塔状态下风洞气动弹性模型试验以及节段模型试验的现象和结果,着重研究了倒角方形截面及该截面桥塔的驰振性能,得出了一些值得研究的结论。本论文的研究内容主要包括以下几个方面：(1)均匀流场中,通过节段模型三分力试验测定带倒角和不带倒角的方形截面的三分力系数,以所得到的三分力系数随攻角变化的曲线作为建立驰振现象的理论基础。根据线性驰振理论来探讨均匀流下两种截面的驰振性能。(2)我们通过引入气动导数H1(气动阻尼对自激升力的影响系数),将驰振的非定常效应纳入考虑,研究该倒角方形截面的驰振性能,并与准定常理论下的结果进行了比较。(3)对倒角方形截面分别施加两种空气动力措施,基于节段试验所得到的三分力随攻角的变化曲线以及气动导数随无量纲风速的变化曲线,研究这两种措施对驰振性能的改善情况。(4)基于Den Hartog准定常理论以及引入气动导数H1的非定常效应的计算方式得到驰振临界风速；将这几种风速结果值和风洞试验所得到的驰振临界风速进行了综合比较。(5)通过均匀流场和紊流场下的裸塔气动弹性模型风洞试验,研究了两种流场下桥塔的风致振动性能。从结构阻尼和气动措施两方面研究了对桥塔气弹试验中驰振的改善情况,并对试验中出现的驰振和涡振耦合情况进行了讨论分析。
[Abstract]:In recent years, the span of the bridge has been increasing, and the height of the main tower of the bridge has been constantly rising, and the tower column is generally a blunt body section, so the wind resistance is poor. The problem of wind-induced vibration under the condition of self-supporting is particularly prominent. In this paper, the phenomena and results of wind tunnel Aeroelastic model test and segmental model test under the condition of bare tower are studied. This paper focuses on the research of chamfer square section and the galloping performance of the bridge tower with this section, and draws some conclusions worthy of study. The research contents of this paper mainly include the following aspects: 1) uniform flow field. The three-point force coefficient of square section with and without chamfer is measured by three-point force test of segmental model. Based on the curve of three-point force coefficient changing with angle of attack, the theory of galloping phenomenon is established. According to the linear galloping theory, we discuss the galloping performance of two sections under uniform flow. The coefficient of influence of damping on self-excited lift takes into account the unsteady effect of galloping. The galloping performance of the chamfer square section is studied, and compared with the results of quasi-steady theory, two kinds of aerodynamic measures are applied to the chamfer square section. Based on the curve of variation of three-point force with angle of attack and the curve of aerodynamic derivative with dimensionless wind speed obtained by segmental test, Based on Den Hartog quasi-steady theory and the unsteady effect of introducing aerodynamic derivative H1, the critical velocity of galloping is obtained. The results of these wind speeds and the critical velocities obtained from wind tunnel tests are compared. The wind tunnel tests of bare tower Aeroelastic model under uniform flow field and turbulent flow field are carried out. In this paper, the wind-induced vibration performance of the bridge tower under two flow fields is studied. The improvement of the galloping vibration in the aero-elastic test of the bridge tower is studied from the aspects of structural damping and aerodynamic measures, and the coupling between the galloping vibration and the vortex vibration is discussed and analyzed.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.3

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