【作者】 唐振兴；

【导师】 罗建辉； 舒兴平；

【作者基本信息】 湖南大学 ， 结构工程， 2011， 硕士

【摘要】 通信塔是一种典型的高耸结构,在通信事业蓬勃发展的今天,其结构安全已与人们的生活息息相关。高耸结构高度较高、重量较轻、刚度较小、外形细长的特点决定了风荷载是其控制荷载,并且随着社会需求的增加和技术的进步,结构向着更高、更轻、更柔和低阻尼的方向发展,使其对风荷载越来越敏感。因此,对高耸结构进行尽量详细的抗风性能分析变得越来越重要。本文以中国移动通信湖南郴州地区GSM第七期扩容建设基站铁塔为工程背景,从结构动力特性、拟静力风响应及风振响应三个方面开展了对在建通信塔的抗风性能分析。本文首先介绍了风荷载的基本特点及相关概念,阐述了风对结构的作用及结构抗风的理论分析方法。利用通用有限元分析软件ANSYS建立了通信塔结构的精确有限元模型,并分析了结构的动力特性,得到了结构的自振频率、振型等动力特性参数。本文采用拟静力风荷载的计算方法,根据《建筑结构荷载规范》和《高耸结构设计规范》计算得到了作用在通信塔结构上不同风向角的拟静力风荷载,在此基础上利用ANSYS静力分析模块分析了通信塔在拟静力风荷载下的响应,并进行了对比分析,得到一些有意义的结论。本文介绍了脉动风荷载的模拟方法及实现过程,根据互功率谱矩阵,利用三角级数的谐波叠加法,采用MATLAB编写了脉动风模拟程序,模拟得到了通信塔不同高度的脉动风速时程,利用ANSYS瞬态动力学分析模块采用Newmark法对通信塔进行了动力时程分析,得到了通信塔在设计风速下的位移、速度、加速度时程,并对其进行对比分析,得到了一些有意义的结论。基于动力时程分析的结果计算了通信塔不同高度的顺风向风振系数,并与根据规范计算得到的风振系数进行了对比分析,发现根据时程分析结果计算得到的风振系数更能反映通信塔顶部平台集中质量的影响,且比根据规范计算得到的风振系数要小。更多还原

【Abstract】 Communication tower is a typical high-rise structure. Nowadays, its structural safety has been closely linked with people’s lives in the booming telecommunications industry. Due to high-rise structures ’ characteristic of high altitude, low stiffness, shape determine, the dominating load of high-rise structures is wind load.The developed direction of the structure is higher, lighter, more gentle and low damping,which make them more sensitive to wind loads with increasing of social demands and technological advances. Therefore, the detailed wind resistance analysis of the high-rise structure becomes more and more important.This paper expounds the wind resistant characteristics of communication towers from the three aspect——the dynamic characteristics, pseudo static response to wind and wind induced response,regarding the seventh expansion construction engineering of Chenzhou, Hunan, China Mobile GSM base station tower as the background.Firstly, it introduces the basic characteristics of wind loads and related concepts, describes the role of wind on structures and the wind resistant theory of structural analysis. The author obtains the natural frequency, vibration mode and other dynamic properties by the analysis of the dynamic characteristics of the structure making use of finite element analysis software ANSYS to establish a precision finite element model of communications tower structure.In this paper, the author chooses pseudo-static wind load calculation method as the research mesures. According to the Load code for the design of building structures and Code for Design of high-rising Structures, calculats the pseudo-static wind load of communications tower structures in different wind direction on the basis of analysising pseudo-static response under wind loads by making use of ANSYS Static analysis module of the communication tower. Meanwhile, the comparative analysises are carried out, and some meaningful conclusions are drawn.This article describes the simulation method and implementation process of fluctuating wind load.In tems of Mutual power spectrum matrix, the author simulates obtainning fluctuating wind speed time series at different heights of the communication tower by using trigonometric series harmonic superposition method, and writes the simulation program of fluctuating wind with MATLAB. Then, the author proceeds to analyse the dynamic time and distance of he communication tower by using Newmark method by the module of ANSYS Transient Dynamic Analysis. At last, the thesis makes some meaningful conclusions with the comparative analysis of the displacement, velocity and acceleration time history of the communication tower under design wind speed.The author caculates the wind-induced vibration coefficients with different height of communication towers based on the results of dynamic analysis, then compares it to the results calculated according to the specification. Throgh this way, the author finds that the wind-induced vibration coefficients based on dynamic analysis can reflect the impact better of the concentrated mass of the platform at the top of communication tower. What is more, the wind-induced vibration coefficients is smaller then the one which is based on the specification., and it’s smaller.更多还原