负保护角羊头型输电杆塔塔头局部杆件布置优化

Optimized layout of members in head of sheep-head type power-transmission tower with negative protecting angle

与传统的酒杯型杆塔相比,负保护角羊头型输电杆塔具有防雷性能好,结构紧凑和节省投资等优点,但是在环境风载作用和断线工况下,塔头关键节点位移、应力和应变显著增大,成为危险隐患。首先提出了塔头关键节点附近杆件优化布置方案,然后利用ANSYS软件,采用桁梁混合模型建立杆塔结构整体有限元模型,分析了不同工况下结构优化前后的受力情况,通过比较证实了优化方案可以显著降低塔头关键节点附近主材的应力水平。

Compared with a conventional cup type power-transmission tower,a sheep-head type power-transmission tower with negative protecting angle has higher lightning protection capability,more compact structure,and less investment outlay. Under wind load or a broken line condition,the high displacement,stress and strain always occur at some key nodes. An optimized layout scheme of members in the tower head was proposed,and then the finite element model of the tower structure was created with the truss-beam model in ANSYS software. The mechanical responses of the tower structure were computed for various working conditions. It was demonstrated by comparison that the stress levels near the key nodes are considerably reduced after optimization.