Influence Of The Fluctuating Component Of The Wind Force On The Dynamic Response Of Cable-Stayed Towers

Abstract

The guyed masts have a complex structural behavior under wind load due to its flexibility and low damping. There are many methods for obtain the response of these structures under wind load, one of them is the static equivalent method “Patch Load”. This has several limitations, the main in related with the consideration of a linear behavior of the structure when is under the fluctuating wind load, recent researches indicated that the static equivalent method can underestimate the internal forces and the displacements, conditioning the need of keep going deeper in the dynamic behavior of guyed masts and development more accurate methods that can describe the structural behavior. The objective of the present paper is identifying the variations in the structural response of the analyzed towers when a dynamic linear and nonlinear analysis of the turbulent component of the wind force is performed through the time history method. A comparison between the axial forces in cables and columns is made, and its obtained the contribution of the resonant and non-resonant response in the fluctuating response of the structure. The models of the study are two guyed masts with different characteristics of stiffness, slenderness and structural composition. The obtained results allow to conclude that exists differences in a range up to 20% in the axial forces due to the wind load when is performed a linear and nonlinear analysis of the fluctuating component of the wind load in both towers.