基于SHM的大跨度斜拉桥风场特性及风效应研究

发布时间：2018-06-20 06:10

本文选题：结合梁斜拉桥 + 实测风场特性　；参考：《东南大学》2015年硕士论文

【摘要】：中国桥梁建设正处于高速发展期,桥梁跨度越来越大,结构越来越轻柔,风致振动成为控制设计的主要因素之一。本文以江苏沿海高速(G15)灌河大桥为工程背景,基于结构健康监测系统统计分析该地区风场特性,对灌河大桥进行颤振和抖振时域分析,主要工作有：(1)基于结构健康监测系统,研究灌河大桥良态气候下风场特性,并进行实测脉动风的非高斯和非平稳性检验。(2)采用Fluent软件对灌河大桥成桥状态下主梁标准断面进行二维流体仿真模拟,识别相应的颤振导数和三分力系数。(3)采用Lin提出的自激力脉冲函数表达式及ANSYS有限元软件,进行桥梁结构颤振时域分析。(4)以实测风谱及规范风谱为依据,模拟灌河大桥脉动风速时程,分析其在设计风速下的抖振响应。得到主要结论如下：(1)统计期间内,灌河大桥基本处于良态气候条件,最大风速不超过15m/s,且主要受东北风的影响,实测风功率谱与各种形式理论谱差异较大,灌河大桥实测脉动风是符合高斯模型的平稳随机过程。(2)流线型断面及π型断面颤振导数及三分力系数识别结果表明,Fluent进行桥梁断面二维气动参数识别具有较大的准确性及合理性；计算得到了灌河大桥成桥状态下主梁标准断面的三分力系数及零度攻角下的颤振导数。(3)提出了桥梁结构自激振动时域计算的“状态假定’法和“重启动迭代’祛,实现了桥梁结构颤振和抖振时域分析的统一化处理。(4)灌河大桥颤振临界风速在172m/s左右,远大于其检验风速47m/s,且受扭转振型阻尼影响很大；灌河大桥在设计风速下的整体抖振响应较小,且考虑自激力时的结果小于不考虑自激力的情况,规范谱作用下的抖振响应大于实测谱下的抖振响应。
[Abstract]:The bridge construction in China is in the period of high speed development, the span of bridge is becoming larger and larger, the structure is more and more soft, and wind-induced vibration becomes one of the main factors controlling the design. In this paper, based on the statistical analysis of the wind field characteristics of the Guanhe Bridge along the coast of Jiangsu Province, the flutter and buffeting time domain of the Guanhe Bridge are analyzed. The main work is: 1) based on the structural health monitoring system. The characteristics of wind field in good climate of Guanhe Bridge are studied, and the non-Gao Si and non-stationary test of the measured pulsating wind are carried out. The fluent software is used to simulate the standard section of the main beam of the bridge under the condition of completion of the bridge. Identification of the corresponding flutter derivative and three-point force coefficient.) the time-domain flutter analysis of bridge structure is carried out by using the expression of self-excited force pulse function proposed by Lin and the finite element software ANSYS. The time-domain analysis of flutter of bridge structure is based on the measured wind spectrum and the standard wind spectrum. The time history of fluctuating wind speed of Guanhe Bridge is simulated and the buffeting response of the bridge under the design wind speed is analyzed. The main conclusions are as follows: (1) during the statistical period, the Guanhe Bridge is basically in a good climate condition, the maximum wind speed is not more than 15m / s, and it is mainly influenced by the northeast wind, and the measured wind power spectrum differs greatly from the theoretical spectrum of various forms. The measured pulsating wind of Guanhe Bridge is a stationary stochastic process in accordance with Gao Si model. The result of identification of flutter derivative and three-point force coefficient of streamline section and 蟺 type section shows that fluent has a larger identification of two-dimensional aerodynamic parameters of bridge section. Accuracy and rationality; The three-point force coefficient and flutter derivative at zero angle of attack of the standard section of the main beam of Guanhe Bridge under the condition of bridge completion are calculated. The "state assumption method" and "restarting iteration" method for the time-domain calculation of the self-excited vibration of the bridge structure are put forward. The unified treatment of flutter and buffeting time domain analysis of bridge structure is realized. The critical flutter velocity of Guanhe Bridge is about 172m/s, which is much larger than its test wind speed of 47m / s, and is greatly affected by torsional mode damping. The global buffeting response of Guanhe Bridge under the design wind speed is small and the result of considering the self-excited force is smaller than that of not considering the self-excited force. The buffeting response under the gauge spectrum is larger than the buffeting response under the measured spectrum.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.27

【相似文献】