摘要
对顺、横风向风荷载同时作用下输电铁塔在两种断线情况下的主要失效模式及其极限基本风压进行研究。按空间桁架体系建立输电铁塔的有限元模型,将顺、横风向的风荷载施加于该模型上,结构中受拉构杆采用弹-塑性单元失效形式,而受压构杆则采用半弹-塑性单元失效形式。建立在风荷载作用下,寻找输电铁塔主要失效模式的方法,该方法以基本风压为控制量,可以方便地获得输电铁塔的主要失效模式及其极限基本风压。通过数值算例指出由于断线后产生了不平衡张力,使输电铁塔的最大可能失效模式的极限基本风压减小,不平衡张力越大,极限基本风压越小;同时指出要提高结构的抗风能力,有效的方法是提高基本失效单元的强度,而这样的单元往往并不多。
Considering two types of wire breakoff, dominant failure modes of a transmission tower and the limit basic wind pressures were analyzed. A finite element model of the transmission tower as a spatial truss structure was established and equivalent static wind loads in the along-wind and across-wind directions were applied. Ductile forcedeformation for tension failure members and semi-brittle non-linear force-deformation for compression failure under buckling were taken into consideration for the tower elements. A method controlled by the basic wind pressure was introduced to generate dominant failure modes of the transmission tower, and the limit basic wind pressures were evaluated. A numerical example indicated that the limit basic wind pressure of the tower at the most probable failure mode became smaller while the unbalance of tension because of wire breakoff increased. It is suggested that in order to improve the structure capacity in resisting wind loads, it is effective and efficient to improve the strength of the basic failure elements and the number of such elements is usually very limited.
出处
《土木工程学报》
EI
CSCD
北大核心
2009年第11期86-90,共5页
China Civil Engineering Journal
关键词
输电铁塔
失效模式
极限荷载
等效静风荷载
断线
优化准则法
transmission tower
failure mode
limit load
equivalent static wind load
wire breakoff
optimal criterion method
作者简介
熊铁华（1968-），男，博士，副教授。主要从事结构可靠度、结构动力学研究。E-mail：thxiong@whu．edu．cn
梁枢果（1950-），男，硕士，教授。主要从事结构风工程、结构动力学研究。
邹良浩（1979-），男，博士。主要从事结构风工程、结构动力学研究。
