| Some existing transmission towers can not meet the requirements of actual bearing capacity because of low early design standard,long operation time and poor maintenance.A lot of research shows that the collapse of the transmission tower is a general instability,and occurs in the main part of the transmission tower,so it is of great significance to study the main leg reinforcement method of the transmission tower.In this paper,a 220 k V ZMC2 transmission tower whose main leg was destroyed in the experiment is taken as the research object,and the reinforcement research is carried out.The main research work is divided into the following three parts:(1)The lattice transmission tower is mainly made of single angle steel,and the connection between the main steel and the main steel is made by bolt joint.Fine Finite element modeling is carried out for the components at the failure position of the main leg of transmission tower,the effects of slenderness ratio,bolt size,bolt preload,Bolt Number and assembly clearance on the ultimate bearing capacity of the main leg are analyzed;(2)In order to avoid the instability of the main leg of the transmission tower,a refined finite element model of the main leg before and after the main leg reinforcement is established by using the cruciform clamp method,the influences of the parameters such as the number of fixtures,the spacing of fixtures,the length of vice-main legs,the pre-tightening force of bolts and the friction Coefficient on the ultimate bearing capacity of main legs are analyzed;(3)Through nonlinear buckling analysis of 220 k V ZMC2 transmission tower,the weak position of the main leg is found out,and the weak position of the main leg is strengthened by the cruciform clamp method,the effectiveness of the cruciform fixture reinforcement method is verified. |
