输电塔-线体系脉动风振耦合分析

Coupling Analysis of Fluctuating Wind Pressure Response for Transmission Tower-Line System

为了研究脉动风引起的结构风致响应,以一塔二线输电塔-线体系为对象,模拟了不同风向角下风荷载导致的结构时程响应.以Davenport风速谱为验算目标来模拟脉动风场,在平均风速的基础上施加脉动风动力时程荷载,分析风向角分别为0°、90°和45°时输电塔-线体系的风振时程响应.依据三种工况下结构中的位移及内力分布情况,分析了主要构件的强度及稳定性,并与基于规范得到的结果进行比较.结果表明,当输电塔层数小于6时,按规范方法计算的强度应力均比按单向流固耦合(Fluid-Solid Interaction, FSI)方法计算的强度应力大;当层数大于6时,按规范方法计算的强度应力与按FSI方法计算的强度应力相当;在45°和90°风向角工况下,按规范方法计算的部分层数的强度应力略小于按FSI方法计算的强度应力.考虑到脉动风的随机性大,建议适当增加风振荷载系数,以确保输电塔-线结构体系的强度安全性.

In order to study the wind-induced response of tower-line structure,a one-tower and two-span transmission tower-line system is taken as the research object to simulate the time-history response of structures under different wind incidence angles.Based on the Davenport wind speed spectrum and the average wind speed,the time histories of fluctuating wind load were applied and the wind-induced response of the tower-line system within time domain was analyzed under 0°,90°and 45°wind incidence angles.According to the displacement and internal force under three working conditions,the strength and stability of the main parts of the transmission tower were analyzed.The obtained results were compared with those calculated using the standard method.It shows that when the number of tower layers is less than 6,the strength stresses calculated by the standard method are larger than those calculated by the fluid-solid interaction(FSI)method;when the number of tower layers is greater than 6,the strength stresses calculated by the standard method are comparable to those calculated by the FSI method;and the strength stresses calculated by the standard method are slightly smaller than those calculated by the FSI method for some layers under 45°and 90o wind angles.Considering the randomness of the fluctuating wind,it is suggested to appropriately increase the load coefficient of the windinduced vibration to ensure the strength safety of the transmission tower-line system.