STATIC-DYNAMIC ANALYSIS OF GUYED MAST TOWERS

Abstract

The objective of this thesis is to carry out the static and dynamic analysis of guyed mast tower when subjected to wind loads. The wind gust is simulated by stochastic process which provides timewise wind velocities. These velocities are then used to determine the wind forces on the mast. A review of literature on the analysis of static and dynamic analysis of guyed mast tower is made. A numerical solution procedure for the solution of static and dynamic analysis based. on Oren's beam model for the mast is adopted. The formulation for both linear and nonlinear behaviour is considered, The cables have been represented by 'Cable element' in which the intermediate degrees of freedom have been condensed to reduce the overall problem of cable guyed mast tower. In the analysis, following nonlinearities are considered.,, (i) large deformations, (ii) variation of cable tensions and (iii) slackening of cables. In the nonlinear analysis incremental—iterative scheme using Newton—Raphson's method has been adopted. Dynamic analysis is carried out using Hilber step by step time integration scheme. An eigen value study has also been carried out which was used in deciding.the time step length and evaluating the Rayleigh's damping. Finally, the conclusions with respect to the linear/ nonlinear static and dynamic analysis of cable guyed mast tower subjected to wind forces are presented.