Control performance evaluation of semi-active tmd subjected to various types of loads

Many types of tuned mass dampers (TMDs), such as active TMDs, multiple TMDs, hybrid TMDs, semi-active TMDs etc., have been proposed to effectively reduce the dynamic responses of a structure. Control performance of a conventional TMD subjected to various types of dynamic loads has been widely studied to date. Although it is known that control performance of a semi-active TMD is better than that of a conventional TMD, control performance of a semi-active TMD subjected to various types of dynamic loads has not been fully studied. Therefore, control performance of a semi-active TMD has been systematically evaluated in this study. To this end, an idealized variable damping device and a magnetorheological (MR) damper are used as semi-active dampers. These semi-active dampers can change the properties of TMDs in real time based on the dynamic responses of a structure. The control performance of STMD is investigated with respect to various types of excitation by numerical simulation. Groundhook control algorithm is used to appropriately modulate the damping force of semi-active dampers. The control effectiveness between STMD and a conventional passive TMD, both under harmonic and random excitations, is evaluated and compared for a single-degree-of-freedom (SDOF) structure. Excitations are applied to the structure as a dynamic force and ground motion, respectively. The numerical studies showed that the control effectiveness of STMD is significantly superior to that of the passive TMD, regardless of the type of excitations.