Wind-Induced Vibration Control on Transmission Tower

Abstract

Transmission towers, which are high rise structures, are susceptible to strong wind forces owing to their high altitude from the ground surface. They are very flexible structures having small damping which is associated with fundamental mode. The wind loads are random dynamic loads which may act from any direction on such towers. Different literature studies show that a significant vibration is generated due to wind induced loads causing stresses to develop in the structural members of the tower. Wind-induced vibration is one of the primary causes for damage to the tower subcomponents which in turn leads to structural failure. So, it is necessary to consider various control strategies for reducing the wind-induced vibration response of tower. This article deals with the use of various energy dissipating devices for response vibration control. Different devices used for vibration control are Viscoelastic damper (VED), Tuned Mass Damper (TMD), Pounding Tuned Mass Damper (PTMD), Magnetorheological (MR) Damper, and Friction Damper. In this paper, a comparative study has been performed based on the control efficiency of these damping devices. VE damper has a special characteristic of dissipating energy thermally but its performance substantially reduces under heavy wind loads. Certain modification in TMD, by combining hybrid of TMD and VED, improves the performance of the damper but it gets larger in size and subsequently its mobility decreases. Semi-active MR damper requires no additional installation space and can reduce all the mode shape dynamic response but it requires an extra electrical energy source to operate. It has been observed that Friction damper overcomes the drawbacks of other dampers and is more efficient in control of wind induced vibration response.KeywordsWind loadTransmission towerVibration controlDampers