台风作用下输电塔线体系动力响应分析

Dynamic response analysis of a transmission tower-line system under typhoon

台风作用下输电线路倒塔事故时有发生。通过Yan Meng台风风场和Monte Carlo法模拟得出了海口市的极值风速和风剖面指数,并采用石沅台风风谱进行了台风脉动风的数值模拟,在ANSYS中建立一塔两线模型,计算了模型在台风风载荷作用下的风载荷效应。分析表明:导、地线线条风载荷对主材轴力的贡献率很大,极值状态时达到了58.9%,通过在台风区适当减小档距或者采用落线护塔的方式可以减小台风带来的损害;台风的高强度和高湍流特性,导致在极值状态下的响应远大于静风等效作用下的响应,规范中所取的风载荷调整系数偏小,对于台风工况,应充分考虑其动力放大作用。

Collapse accidents of transmission tower-line systems under typhoon occur frequently. Here,the extreme wind speed and wind profile index were simulated using Monte-Carlo method and Yan Meng typhoon field,the fluctuating wind of typhoon was calculated using Shiyuan typhoon spectrum. A model consisting of one tower and two-span conductors was established with the FE software ANSYS,and the wind load effect of the model was calculated under typhoon wind load. The analysis indicated that the wind load of conductors and ground wires make a significant contribution to the axial force of principal members,the contribution rate reaches 58. 9% during extreme value status of typhoon; the damage due to typhoon can be reduced through appropriately decreasing span distance or dropping lines to protect towers in typhoon region; the dynamic responses of the model during extreme value status of typhoon are much larger than those of the model during the equivalent static wind status due to high strength and high turbulence ＇s characteristics of typhoon; the adjustment coefficient of wind load in the existing design code seems to be smaller,its dynamic amplification effect must be fully considered under typhoon condition.