Stability Analysis And Reinforcement Research Of High-voltage Steel Angel Transmission Tower

With the rapid development of electric power construction in China,the electrical power system acts as an important component of the state construction and citizens’ lives,its safety will directly influence the harmonious development of society.The large power grid accident will not only cause huge economic losses,but also trigger social chaos.In recent years,there were a number of power transmission towers collapsing in Chinese power grid system,and the wind damage is the main factor.To solve this problem,the best way,of course,is to tear down and rebuild the old power transmission towers.But the redesign of transmission lines and rebuild of towers cost too much,the construction period is too long as well,so the implementation is very difficult.Base on it,the research of adopting effective methods to strengthen the old tower to improve its abilities to resist disaster is very necessary.This paper is based on the research project of “Research on reinforcement technology of transmission tower in service” of Guangdong Power Transmission and Transformation Company of China Southern Power Grid.And selecting ZGU3 tower,which is the representative tower model in those old towers,as the study object,the mechanics property analysis and a series of reinforcement researches were carried out.The main contents include several parts as follows:(1)The finite element modeling method of transmission tower was researched by APDL,which is the parameter design language of ANSYS,and refined three-dimensional finite element model of ZGU3 tower was established.(2)The eigenvalue buckling analysis and nonlinear buckling analysis of ZGU3 tower under four working condition was researched by ANSYS.And the ultimate wind speed and weak part in different working conditions were obtained according to the nonlinear bucklinganalysis.It showed that the weak part of ZGU3 tower mainly appeared in the principal members of the tower lower parts combined the analysis results.(3)An reinforcement which composed by steel plate,fixture and high-strength bolt was adopting to strengthen the weak parts of the tower.To study the effectiveness of this device,twelve specimens were simulated by ANSYS,and the results were compared with test results.And on this basis,the effect of this method in the weak part of ZGU3 tower was investigated.At the same time,the influence analysis is made on the width,thickness,yield strength of steel plate and the initial gap between steel plate and angle steel.(4)The equivalent yield stress of a reinforced member was calculated by the formula of critical stress calculation which based on the edge yield criteria,and the accuracy of this calculation was verified by ANSYS.Then,the equivalent yield stress was applied in nonlinear buckling analysis of the reinforced tower,and the ultimate wind speed and weak part were compared with the analysis results of unreinforcement tower.