输电塔线体系非线性地震反应分析

地震对输电塔线的安全运行产生了威胁。选择输电线路工程中常用的5A-ZM4猫头塔为研究对象,利用ANSYS软件建立两塔三线输电塔线体系有限元模型,计算塔线体系的自振频率和振型并分析影响其动力特性的主要因素。选用天津波、EI-Centro波、上海人工波3条典型地震波,通过调整加速度峰值的方法研究塔线体系的位移响应非线性行为以及弹塑性极限状态。分析结果表明,强震作用下塔线体系进入非线性极限状态时,塔顶最大位移主要集中在H/200~H/100（H为塔高）之间;塔身第2至第3横隔之间杆件将率先进入弹塑性极限状态,产生较大塑性变形,使体系表现出较强的非线性特征。

Nonlinear Dynamic Response Analysis of the Transmission Tower-Line System under Earthquake

With the 5A-ZM4 cat-head transmission tower as an example, a finite element model of transmission tower-line system consisting of two towers and three lines is established by using ANASYS software. The dynamic characteristics of natural frequencies and vibration modes of the system are calculated and the influencing factors are analyzed. Based on 3 typical seismic records of Tianjin wave, EI-Centro wave and Shanghai artificial seismic wave, the peak values of the accelerations are scaled up to consider the nonlinear behaviors and plastic limit of transmission towers. The results show that the largest displacements on top of the tower are mainly concentrated between H/200-H/100 (H is the height of tower) in the nonlinear ultimate limit state under earthquake; and that the bars between the second and the third diaphragms of the tower fall first into elastic-plastic limit state and produce large plastic deformation, indicating a strong nonlinear characteristics of the system.