Failure Analysis Of Transmission Line Towers

Abstract

newlineOverhead transmission lines play an important role in the operation of electrical power system and the national economy depends enormously on newlinesafe and reliable availability of power lines The overall objective of the newlinestudy is to investigate the various failures encountered in transmission line newlinetowers and to investigate the deficiencies in the present design and analysis newlinemethods of transmission line towers with respect to strength and behaviour newlineThe effect of secondary bracing hip bracing patterns and the effects of joint newlineslip on the overall performance of transmission line towers is studied newlineIn the first phase experimental studies on single angle sections full newlinescale test on transmission line towers for different load conditions and newlineexperimental investigation on the effects of boltslip at joints on the newlinedeformation behaviour of transmission line towers are undertaken Influence newlineof large width to thickness ratio in hot rolled angle section is also studied newlineWhen the angle sections are used in transmission line towers they tend to fail newlinebefore the estimated buckling strength Various codes of practice consider newlinedifferent methods for limiting the width to thickness ratios of angle section to newlinereduce buckling Experiments were conducted on single angle members with newlineslenderness ratio less than 40 Eight different sizes of angles with different newlineyield stress and with width to thickness ratio varying from 13 to 167 are newlinechosen The test on a fullscale prototype tower with different voltage rating newlineand with different configuration is conducted based on the approved newlinestandards Several loading conditions are considered which include normal newlineloading condition broken conductor condition and simultaneous breaking of newlinetwo conductor condition newlineThe leg member of a transmission line tower is connected with newlineseries of lap or butt joints and their effect on the deflection of the tower is newlinestudied in detail Present investigation is mainly to quantify the bolt slip and newlinethe load at which it occurs in the transmission line towers newline newline