The Impact On Transmission Tower’s Load And Deformation Caused By Iced Wires Breakage

In winter, due to the low temperature, transmission conductor can produce non-circularcross-section of ice, especially under the condition of wire breakage, combined with the effectof wind load, the safe operation of the transmission line tower system has a great influence,soit is of great significance to study the impact on transmission tower’s load and deforformationcaused by iced wires breakage.Large span upright-tension towers-upright tower finite element model is built up by fi-nite element program software ANSYS,and use spring element to simulate the stiffness effectcaused by across the conductor and insulator, makes the model more relevant to the enginee-ing practice; For transmission tower-line system conductor for shape analysis was obtainedunder the condition of gravity conductor; The conductor model is loaded by aerodynamic toprove the validity of the program.In order to study the impact on transmission tower’s load and deformation caused by icedwires breakage, considering the size of wind speed and ice thickness of wires. At low windspeed and wire thin ice, with the increment of wire breakage, disconnect phase conductor isless dancing, as for the continuous line and the amplitude of performance for the same phaseconductors under all conditions of amplitude were similar, but different phase conductorsunder the same conditions’ amplitude difference is very big. Transmission tower advocatematerial on the maximum stress of wire fracture increases with increasing of the number andare unified location in power transmission tower, and the matching of condu-ctor wave shapeis different, the maximum stress due to transmission tower does not exceed the yield limit ofmaterial, and the transmission tower under the condition is still in a safe state.The force and deformation of the transmission tower were studied at low wind speedwire and thick icing under upper, middle and down location of the wire breakage. When one or twowires were broken, the force, deformation and galloping law of the transmission tower weresimilar to low wind speed wire thin icing conditions. But when three wires were broken,fra-cture transmission tower damage developed different forms. When three wires of the transmissiontower were broken at the relative position, the oblique and auxiliary materials of transmission towers weredamaged due to large twist, as the two across of transmission towers developed a large imbalancetension and photogenic part of the transmission tower generated a large torque. When threewires of the transmission tower were broken at the relative middle position, the load appliedon transmission towers is uniform and greater stress exceeds the yield limit of the material ontransmission towers main material, which caused buckling failure and transmission towercould partially collapse due to the stress redistribution. When three wires of the transmissiontower were broken at the bottom position, the excessive load caused largedeformation at thebottom material of transmission tower because of the eccentricity of transmission tower, and this condition had the greatest harm to the transmission tower.The impact on stress and deformation of transmission tower under the high wind speedand thin ice of wires were studied. Study shows that the transmission tower1wire was brokenlocated in the up phase, will lead to the transmission tower’s maximum stress exceed the yieldlimit of the material and buckled, because the force on the transmission tower will increase bywind speed increases; when the transmission tower1wire was broke located in the middleand bottom phase, the left and right sides are opposite phase, transmission tower will cause alarge deformation in the bottom material be due to "eccentric", this could lead to transmissiontower overall collapse.This paper, by using the finite element program ANSYS numerically simulated variousconditions of stress and deformation of transmission tower under wire breakage, provides atheoretical basis for engineering application.