School of Civil Engineering, Hunan University of Science and Technology

以某倒塌事故终端塔塔-线体系为对象,建立其有限元动力学分析模型,基于谐波叠加法和Davenport目标谱模拟风速时程,确定覆冰塔线上的风荷载,研究覆冰终端塔塔-线体系的风致倒塌过程、机理及其影响因素.通过瞬态分析模拟覆冰终端塔塔-线体系的整个倒塌过程,揭示其风致倒塌机理.覆冰终端塔在8级大风荷载作用下,背风侧塔腿下部主材最先失稳,并导致塔腿部位其他相邻构件应力增大,依次发生局部构件失稳或屈服失效,最终诱发输电塔整体结构失稳倒塌.终端塔的整个导线张力都是非平衡张力,在塔腿部位会产生很大的倾覆应力.在失效构件等效应力的荷载占比中,导线张力占比大于50%,其次是作用在塔上的风荷载,占比大于30%.通过参数影响分析得出,90°风向角是一种最危险的风荷载工况,而最合理的线路走向则是沿终端塔底座截面两根正交的最大惯性主轴.

The finite element dynamic analysis model is developed by using the collapsed terminal tower-linesystem as the object. Based on the harmonic superposition method and Davenport target spectrum, the timehistory curve of wind speed is simulated to determine the wind load on the iced tower-line. The investigationfocuses on the wind-induced collapse mechanism and influencing factors of iced terminal tower-line system.Transient analysis is used to simulate the whole collapse process of the iced terminal tower-line system in order toreveal its wind-induced collapse mechanism. Under the action of eight grade wind load, the lower primarymaterial of tower leg on the leeward side is the first to become unstable failure, which increases the stress ofadjacent components. The iced terminal tower then suffers from instability or yielding failure of the localcomponents in sequence, eventually causing the entire structure to collapse. The entire conductor tension in theterminal tower is non-equilibrium, which produces significant overturning stress in the tower leg. On the loadproportion of equivalent stress of the failed elements, conductor tension accounts for more than 50%, and windloads acting on the tower for more than 30%. The analysis of parametric influences leads to the conclusion thatthe wind direction angle of 90 degrees is one of the most dangerous wind load circumstances, while the mostreasonable line direction is along the two orthogonal maximum inertia spindles of the cross section of terminaltower base.

湖南省自然科学基金资助项目(2023JJ30259)

张淳淇,谢献忠,易润华,等.覆冰输电线路终端塔风致倒塌机理[J].湖南科技大学学报(自然科学版),2024,39(3):52-60.

ZHANG C Q, XIE X Z, YI R H, et al. Wind-induced Collapse Mechanism of Terminal Tower of Iced Transmission Line [ J] .Journal of Hunan University of Science and Technology ( Natural Science Edition) , 2024, 39( 3) : 52-60.