格构式复合材料电杆结构设计及承载性能分析

Structural Design and Bearing Capacity Analysis of a Lattice FRP Transmission Pole

根据沿海台风地区气象条件,计算了大风工况下格构式纤维增强复合材料(FRP)电杆的设计荷载,确定了电杆结构布置型式和杆件规格。考虑服役周期内结构大变形和FRP老化的影响,采用通用有限元软件ANSYS完成了格构式FRP电杆结构分析;与承载性能相同的常规混凝土电杆相比,单根电杆重量可降低60%以上。为验证格构式FRP电杆的承载性能,完成了90°大风100%设计荷载工况和超载工况下的电杆结构真型试验,获得了沿高度方向的杆身位移和典型构件断面的应变,并与有限元计算得到的杆顶位移和主材断面应力进行了对比分析。研究结果表明,格构式FRP电杆杆件在250%设计荷载内均处于线弹性阶段,其中主材断面应力最大值159.8 MPa,低于FRP材料的屈服强度300 MPa;有限元计算得到的杆顶位移和主材断面应力与试验结果基本一致,当加载至约260%设计荷载时,FRP电杆根部侧面加固板孔壁发生剪切破坏。

According to the meteorological conditions in littoral typhoon areas, the designed load of a lattice FRP transmission pole is calculated under high wind condition, and the structural arrangement pattern and member sizes of the FRP transmission pole are determined. With consideration of the large deformation and aging effects of the FRP transmission poles in their service period, the general finite element analysis software （ANSYS） is used to make a structural analysis of the lattice FRP transmission pole. Comparing with the conventional reinforced concrete transmission pole, the weight of the FRP transmission pole can be reduced over 60%. In order to check the bearing capacity of the lattice FRP transmission pole, prototype tests are conducted respectively under 100% designed load and overloading condition with 90 degree high wind load. The displacements of the pole body along height direction and the strains at typical member sections are obtained and compared with the calculated displacements at the pole top as well as the stresses of main members by FEA method. It is indicated that when the testing load is less than 250% of the designed wind load, all the members are in linear elastic state with the maximum stress of the main members being 159.8 MPa, much lower than the yield stress of 300 MPa for FRP; the displacements at the pole top as well as the stresses of the main members calculated by FEA model are basically consistent with the testing values; when the testing load is over 260% of the designed wind load, shear failure occurs on the hole wall at the bottom of the lattice FRP transmission pole.