悬垂绝缘子串动态风偏角有限元分析

有别于传统的刚性直杆静力学法, 利用有限元方法计算悬垂绝缘子串在脉动风作用下的风偏角,首先模拟考虑空间相关性的脉动风速时程并转换为风荷载时程; 然后利用梁单元模拟输电塔钢结构杆件, 杆单元模拟悬垂绝缘子串, 索单元模拟输电线, 建立塔- 绝缘子串- 输电线的有限元耦合模型。使用逐步积分法计算平均风激励、一致脉动风激励、不考虑塔- 线耦合的脉动风激励和考虑塔- 线耦合系统与空间相关性的脉动风激励4 种情况下悬垂绝缘子串的最大风偏角度, 并与传统的静力学方法对比。分析发现, 传统的静力学方法忽略了体系的动态响应, 使风偏角偏于不安全; 考虑塔- 线耦合体系与空间相关性的脉动风激励的模型能够综合各种因素, 得到较为合理的风偏角。

Finite Element Analysis of Dynamic Windage Angle of Suspended Insulator Strings

Different from traditional rigid bar static method,finite element method is used to calculate windage angle of suspended insulator string under fluctuating wind.First,the fluctuating wind time history considering space relevancy is modeled and converted to wind load time history.Then,coupled tower-insulator string-conductor finite element model is established by modeling tower members,insulator string,and conductor with beam element,bar element,and string element,respectively.Maximum windage angle of insulator string under four conditions,including average wind excitation,consistent fluctuating wind excitation,fluctuating wind excitation without tower-conductor coupling and with both coupling and space relevancy,are calculated using static method and stepwise integration method.Comparing to traditional method,results show that windage angle predicted by static method is non conservative;results from present method are more reasonable.