Optimum damping of slender monopole towers by gyroscopic stabilizer

Slender structures as lighting poles and telecommunication towers are usually very sensitive to wind effects due their dynamic characteristics and due to their notable exposure to wind forces. Wind-induced forces produce fluctuating stress, which, despite the assessment of dynamic properties and the study of the environmental conditions, can lead to damage accumulation and consequent collapse of these structures. Careful attention to wind forces has, therefore, to be paid for these typologies of structures, since several damages have been attributed to fatigue issues. It is well known that damping and structural frequencies play a fundamental role in the structural response under wind loads; in fact, an increase of damping would lead to remarkable beneficial effects on the dynamic response of these structures. This paper focuses the attention on a mathematical model of a damped gyroscopic device conceived as a dynamic stabilizer for such slender structures; the proposed mechanical device allows for an increase of structural damping with a consequent improvement of dynamic performances of the tower subjected to wind loads. A parametric study for different mechanical properties of the gyroscopic device has been conducted in the present paper aiming to assess the effectiveness of the proposed apparatus for different configurations of the proposed device.