某广电发射塔风振响应分析

Wind Induced Vibration Response Analysis of a Broadcasting and TelevisionTransmission Tower

本文针对作用在广电发射塔的风荷载特点,采用线性滤波法(AR法)编制了风场模拟程序,合成了符合Davenport谱的风速时程曲线,可应用于高耸结构的脉动风荷载模拟。以某带平台广电发射塔为例,采用SAP2000建立有限元模型并计算结构的风振响应,对比不同计算方法下风振系数分布特点,可知对于质量刚度突变的高耸结构,采用时程分析与频域分析的风振系数吻合度非常好,说明在此类工程中可以直接采用考虑多振型计算的频域法计算风振响应。

A wind field simulation program is created using the linear filtering method(AR method)to simu-late wind load vibrations on tall structures,based on the wind load characteristics acting on broadcasting and tel-evision transmission towers.The program synthesizes a wind speed time history curve that conforms to the Dav-enport spectrum.To demonstrate the programs effectiveness,a broadcasting and television transmission tower is used as an example in this paper.A finite element model is established,and the wind vibration response of the structure is calculated using SAP2000.The distribution characteristics of the wind vibration coefficient are compared under different calculation methods.The results show that for high-rise structures with sudden changes in mass stiffness,the wind vibration coefficient obtained by the time history analysis is in good agreement with the frequency domain analysis.This indicates that the frequency domain method considering multi-mode calcula-tion can be directly used to calculate the wind vibration response of broadcasting and television transmission tow-er.