A STUDY OF NON-LINEARITY IN GUYED MAST TOWER

Abstract

This thesis deals with the three dimensional analysis of guyed mast towers by a matrix displacement method when subjected to wind loads. Considering the three dimensional behaviour of the structure a detailed parametric study is performed to study the influence on its load - response characteristics of some of the important geometric and stiffness parameters of the mast. In this analysis a study is made of nonlinearity arising due to (i) beam-column effect of the mast, (ii) large deformations, and (iii) cablg sag. Analysis of this nonlinear problem is performed by an iteration procedure. The loads on the structure are converted into a set of concentrated nodal loads. A fortran computer programme is used for the analysis. Two towers are chosen for analysis, a medium height tower of 122 m height and a tall tower of .467 m height. The applied wind load is treated as uniform throughout the height of the structure. The various parameters considered for analysis are; effective modulus of elasticity of cables, moment of inertia of the mast, initial tension and stiffness of cables. Finally a study is made to study the influence of any one cable breaking at a time. iii