Stress Analysis And Structure Optimization On Tower Foot Plates Of Transmission Lines

The tower foot plate is the connecting part at the bottom of the transmission tower.The transmission tower and the foundation are connected by the tower foot board.The strength and rigidity of the tower are crucial to the safety of the entire transmission line.As the voltage level increases in china,the transmission tower bears load increases and the structural size of the transmission tower also increases.The tower foot plate getting bigger and thicker,which brings a series of problems.The oversized and thick tower foot plate brings difficulties to the manufacture and installation;especially for the circular tower foot plate,the thick tower foot plate is difficult to weld,this may causes tearing damage on the connecting steel pipe,which jeopardizes the safety of the structure.At present,there are few research on the thickness reduction of the tower foot.This paper mainly studies the thickness optimization of square tower foot plates and circular tower foot plates.For the square tower foot plates,the combination of mechanical analysis and finite element analysis is used to guide the thickness of the bottom plate.The nuclear method and two measures to reduce the thickness of the square plate(arrangement of eight bolt holes or twelve bolt holes)were proposed,and it was verified that both of the above measures can reduce the maximum bending stress in the bottom plate,thereby reducing the plate thickness.For the circular tower foot board,similar to the research process of the square tower foot board,guided by the specification,the method of mechanical analysis and finite element analysis is combined to study the method of checking the thickness of the bottom plate of the circular tower,and a new tower is proposed and designed.The foot pad and the finite element calculation verified that the mounting pad can reduce the maximum bending stress in the bottom plate,thereby reducing the thickness of the plate,even after considering the quality of the block,it can save material.At the end of the chapter,a preliminary study on the deformation of the circular tower foot due to the large bending moment is carried out,and the basic equations of the deformation are listed.This part lays the foundation for the next stage of research work.Aiming at the new eight-bolt arrangement of the tower foot plate proposed in this paper,the true test of the bearing capacity of the gusset plate is carried out.Through the large number of strain gauges arranged on the tower foot plate,the measured point strain data under various load conditions are obtained.The analysis results show that the measured data is in good agreement with the finite element calculation results,which verifies the reliability of theoretical research and numerical calculation,and provides effective experimental data support for the determination of the new tower foot design method.In this paper,from the theoretical research,numerical calculation and true type test,a lot of research work is carried out on the tower pin node of the transmission tower.The obtained research results provide a basis for the optimal design of the tower foot plate and have good engineering application value.