下击暴流风冲击作用下输电塔非平稳动力响应的频域方法  

FREQUENCY DOMAIN METHOD FOR DYNAMIC RESPONSES OF TRANSMISSION TOWER UNDER DOWNBURST

作　　者：汪大海[1] 王国强 王昕 孙启刚 杨庆山[5] 黄国庆 杨军永 WANG Da-hai;WANG Guo-qiang;WANG Xin;SUN Qi-gang;YANG Qing-shan;HUANG Guo-qing;YANG Jun-yong(School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China;Wuhan Engineering Construction Law Enforcement Inspection Station,Wuhan 430024,China;Tongyuan Design Group Co.,Ltd.,Jinan 250101,China;State Grid Shandong Electric Power Company,Institution of Economy and Technology,Jinan 250000,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China;State Grid Shandong Electric Power Company,Laiwu Power Supply Company,Jinan 250000,China)

机构地区：[1]武汉理工大学土木工程与建筑学院,武汉430070 [2]武汉市工程建设执法稽查站,武汉430024 [3]同圆设计集团股份有限公司,济南250101 [4]国网山东省电力公司经济技术研究院,济南250000 [5]重庆大学土木工程学院,重庆400045 [6]国网山东省电力公司莱芜供电公司,济南250000

出　　处：《工程力学》2024年第8期152-163,共12页Engineering Mechanics

基　　金：国家自然科学基金项目(51878527,51720105005,51478373)。

摘　　要：下击暴流是强对流天气下的一种局地极端风,具有尺度小、风速大、突发性等特点,是导致输电线路风灾破坏的主要原因之一。开展下击暴流风冲击作用下输电塔风振响应的计算理论研究具有重要的意义。论文依据时变平均风和非平稳脉动风场的理论模型,给出移动下击暴流冲击风荷载在时域及频域表达式;继而基于随机振动理论,推导建立了输电杆塔非平稳脉动风振响应的频域解析方法,再通过首次超越极值理论,给出了非平稳下击暴流作用下输电杆塔响应极值的精确分布。进一步,论文探讨了将原有不同步非平稳下击暴流脉动风激励视为同步且慢变过程近似结果的精确性,并在此基础上提出了平稳等效的极值分布和峰值因子的实用简化计算方法。论文采用随机样本的有限元瞬态动力分析结果,检验了上述频域理论方法的精确性。研究表明:该文提出的非平稳响应极值分布的理论解精确性高、同步慢变激励简化得到的等效平稳方法计算便捷且结果略偏保守。该文研究为推动建立输电杆塔抗下击暴流设计体系提供了计算理论基础和技术支撑。Localized severe wind such as downbursts is responsible for structural failures of transmission lines because it is always characterized by small size,high intensity and sudden change.The purpose of the study is to search a theoretical analysis framework for investigation of the dynamic response of transmission towers under downburst attack in frequency domains.To begin,using the theoretical model for time-varying mean wind and for non-stationary fluctuating wind,the expressions of impacting wind load on a transmission tower by the moving downburst in time and frequency domain are developed respectively.Upon the random vibration theory,the frequency domain solution of non-stationary fluctuating wind-induced response of transmission towers is proposed.Subsequently,through the extreme value theory of first-passage,the extreme value probability distribution of dynamic response under the non-stationary downburst wind load was proposed in theoretical approach,as well as the simplified solution for peak factor by equivalent stationary extreme value distribution are supplied.The accuracy of the frequency-domain theoretical method was verified using the finite element transient dynamic analysis results of random samples.This study indicated that the multi-source non-stationary excitation at different heights of the tower can be simplified to synchronous slow-varying excitation.The theoretical solution of non-stationary response extremum distribution has high accuracy,and the peak factor by equivalent stationary extreme value distribution is convenient and slightly conservative.The study provides a theoretical basis and technique for the improvement of thunderstorm-resistant design of transmission towers.

关 键 词：下击暴流 输电塔 非平稳脉动风 频域响应 极值分布 

分 类 号：TU973[建筑科学—结构工程]