Optimization criteria for the TDM design in slender structures excited by wind load

The Tuned Mass Damper (TMD) is the simplest of the passive control devices used in many slender structures to protect them from damages and failure produced by dynamic loads. A single TMD is used to control vibrations in a real structure when a single vibrational mode involves the greatest part of the modal mass. This paper deals with the reduction of vibrations in slender structures due to the wind load. The structure is modelled as a Single Degree of Freedom (SDoF) system and the wind load is estimated through the pre-filter technique: the aerodynamic force is a function of a filtered White Noise. Several optimization criteria have been proposed to estimate the optimum TMD design parameters that provide the best performance in the structural vibration reduction. Two different criteria to optimize the frequency and the damping ratio of the TMD are here proposed. The reduction of the displacement and the acceleration of the structure at its top are the aims respectively of the first and the second optimization criteria proposed. A comparison of the design parameters and the performance obtain from the application of the two criteria is presented. Moreover, sensitivity analyses for different environment conditions and system configuration are carried out. The comparison of the two optimization criteria and the sensitivity analyses show that the acceleration criterion is more attractive. Finally, the two optimization criteria are applied to estimate the TMD design parameters to reduce the vibrations due to the wind load in a lighting tower