断线张力是输电线路倒塔的最重要因素之一.利用非线性有限元理论,针对500kV猫头式输电塔,研究了10种加载模式下的极限承载力和破坏形式.计算结果表明,不同的加载模式下输电塔架的破坏形式可以分为三个类型:塔架整体弯曲失稳破坏、从加载点开始杆件逐步进入塑性导致的整体失稳破坏和第一段塔腿斜撑及辅材面外失稳造成的整体失稳破坏.在承受扭矩和较大偏心的加载模式下,塔架的整体扭转承载能力相对较弱;当扭转达到临界角度时,塔架必然屈曲,直至最终破坏. The disconnection tension is one of the most important factors in the downconversion of power transmission lines.Using the nonlinear finite element theory, the ultimate bearing capacity and failure modes of the 500kV cathead transmission tower under 10 loading modes are studied. The calculation results show that, Under the loading mode, the damage forms of the transmission tower can be divided into three types: the whole bending instability of the tower is destroyed, and the rod begins to enter the plasticity and causes the overall instability and damage and the first section of the tower legs and the bracing and auxiliary The overall instability damage caused by the out-of-plane instability of the tower, the overall torsional load carrying capacity of the tower is relatively weak under the loading mode with torques and large eccentricities; when the critical angle of torsion is reached, the tower must buckle until finally destroyed .