AN ACTIVE MASS DAMPER FOR VIBRATION CONTROL OF A SLENDER STEEL STRUCTURE

This paper describes the application of an Active Mass Damper (AMD) to control the vibrations of a steel truss tower placed on the top of a hill in Tuscany (central Italy). The device is manufactured with two linear motors that actuate two moving masses placed perpendicular to each other to independently control the components of the in-plane oscillation. First, a Finite Element Model (FEM) of the structure is developed and calibrated based on an Experimental Modal Analysis (EMA). The model is adopted at the design stage for dimensioning the AMD, based on the forces required to significantly improve the system structural damping. Then, the experimental results obtained in the field are reported for the structure subjected to wind loads, both with the AMD activated (controlled structure) and with the AMD switched off (uncontrolled structure). The improvements of the system dynamics introduced by the AMD is demonstrated in terms of damping increase and oscillation reduction when the structure is subjected to variable wind loads.