桥塔自立状态风致振动试验研究及TLD控制系统设计

发布时间：2018-05-30 05:03

本文选题：桥塔 + 自立状态　；参考：《长安大学》2017年硕士论文

【摘要】：随着我国桥梁建设水平和建设质量的提升,桥梁的跨越能力也越来越强,桥塔的高度也越来越高,桥塔的刚度也随之减小,因此,大跨径斜拉桥和悬索桥桥塔的抗风性能和美学性能是当前值得研究的重要课题之一。在现代大跨径桥梁的建设过程中,桥塔没有索和梁体系的约束,很长时间处于自立状态。在此期间,与桥梁完全建成时相比,桥塔对风荷载更为敏感,因此,自立状态下桥塔风致振动问题是影响设计方案和桥塔选型的关键因素之一。低阻尼的钢桥塔易受横风向的作用,而对于高度很高的混凝土桥塔同样存在这一问题。混凝土桥塔数量上远远超过钢桥塔,它的开裂甚至破坏更是不可逆的,造成的结果更为严重。同时对施工过程中的现场施工员和施工机具的作业安全性也有很大的影响。本文通过双柱式桥塔的风洞试验,对比FLUENT模拟结果,分别得到迎风侧单柱、背风侧单柱和单柱的三分力系数,根据结果选定要研究的风向角,在单一变量塔柱间净距比变化的过程中,研究塔柱间气动干扰效应对桥塔静三分力系数的影响,为桥塔设计提供数据支持;使用ANSYS通用有限元计算软件对桥塔进行了动力特性分析,在风洞实验室制作了试验模型,模拟风场进行了桥塔气弹模型风洞试验,研究了风荷载作用下桥塔的动力响应,并收集其他桥塔风洞试验资料,考虑风荷载对桥塔选型的影响。此外,本文针对桥塔的风致振动控制措施进行了研究,介绍TLD设计流程并通过试验证明,自立状态下施加调液阻尼器经济方便,快捷有效,可以为以后同类桥塔TLD设计积累经验。本文的主要结论:1)通过风洞试验发现,双柱式桥塔由于气动干扰效应的存在会影响其静三分力系数,在Fluent数值模拟结果中同样得到验证,归纳出规律。2)改变塔柱间净距与塔柱宽度的比值,进一步探究塔柱间气动干扰的规律,得到双柱式桥塔之间净距应满足5~6倍或者10倍以上塔柱宽度的设计区间,通过气弹模型风洞试验反面论证结论。3)针对前文设计区间之外而出现涡振的桥塔气弹模型,提出采用TLD这种减振措施,并通过风洞试验验证其可行性。
[Abstract]:With the improvement of bridge construction level and construction quality in our country, the span ability of bridge is becoming stronger and stronger, the height of bridge tower is higher and higher, and the stiffness of bridge tower is also decreasing. The wind resistance and aesthetic performance of long span cable-stayed bridge and suspension bridge tower are one of the important topics worth studying at present. In the process of modern long span bridge construction, the tower has no constraints of cable and beam system, so it is in a state of independence for a long time. During this period, the tower is more sensitive to wind load than when the bridge is completed. Therefore, the wind-induced vibration of the tower under self-supporting condition is one of the key factors affecting the design scheme and the selection of the bridge tower. The steel bridge tower with low damping is easy to be affected by cross wind direction, but this problem also exists for the high height concrete bridge tower. The number of concrete tower is far larger than that of steel bridge tower, and its cracking and even destruction are irreversible, and the result is more serious. At the same time, it also has a great influence on the safety of construction workers and construction tools. Through wind tunnel test of two-column bridge tower and comparing with FLUENT simulation results, the three-point force coefficients of upwind side single column, leeward side single column and single column are obtained, and the wind direction angle to be studied is selected according to the results. In the process of the change of net distance ratio between single variable tower columns, the influence of aerodynamic interference effect on the static three-point force coefficient of bridge tower is studied to provide data support for tower design. The dynamic characteristics of the bridge tower are analyzed by ANSYS finite element calculation software. The test model is made in the wind tunnel laboratory, and the wind tunnel test of the aero-elastic model of the bridge tower is carried out by simulating the wind field. The dynamic response of the tower under the wind load is studied. The wind tunnel test data of other towers are collected and the influence of wind load on tower selection is considered. In addition, in this paper, the wind-induced vibration control measures of bridge tower are studied, and the design flow of TLD is introduced. It is proved that the application of liquid damper in self-supporting state is economical, convenient and efficient. Can accumulate experience for similar tower TLD design in the future. The main conclusion of this paper is: (1) through wind tunnel test, it is found that the static three-point force coefficient of double-column bridge tower will be affected by the existence of aerodynamic interference effect, which is also verified by Fluent numerical simulation results. (2) changing the ratio of the net distance between the towers to the width of the column, and further exploring the laws of the aerodynamic interference between the towers, and obtaining the design interval of the net distance between the twin column bridges that should be 5 or 10 times the width of the tower column. In view of the aero-elastic model of bridge tower which appears vortex vibration outside the previous design section, this paper puts forward the method of adopting TLD to reduce the vibration, and proves its feasibility by wind tunnel test.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U446.1;U441.3

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