输电塔塔线体系风振响应分析

Wind-induced dynamic response of a transmission tower-line system

基于风洞试验得到的输电塔线性一阶广义荷载谱,推导了一般性的输电塔顺风向、横风向脉动风荷载功率谱公式。利用此功率谱,模拟了塔线体系顺风向、横风向脉动风荷载。对输电塔线体系及单塔的动力特性进行了分析,分析表明,在远低于单塔同阶振型的自振频率时,塔线体系中的输电塔平面外振型就会与导地线振动耦合。对单塔及输电塔-线体系进行非线性动力时程分析,得到了位移、加速度和内力等响应的时程,对比了有、无横风向脉动风荷载的风振响应,并分析了风振响应的功率谱。

Power spectra expressions of along-wind and cross-wind fluctuating wind load acting on a transmission tower were deduced based on the fundamental linear modal generalized force spectra obtained through a wind tunnel test.Time histories of along-wind and cross-wind fluctuating wind load were simulated based on these spectra.Dynamic characteristics of a single tower and a trans mission tower-line system were analyzed.The results showed that The out-plane vibration modes of the tower in the system are possible to be coupled with vibration of cables,even their frequencies are far below the same order natural frequencies of the single tower;time histories of displacement,acceleration and internal force et al are obtained based on nonlinear dynamic time-history analyses of the transmission towers-line system and the single tower.The wind-induced response spectra and diffences between the response to across-wind loads and that without those loads were analyzed.