On energy dissipation or harvesting of tuned viscous mass dampers for SDOF structures under seismic excitations

Abstract

In the past decade, tuned viscous mass dampers (TVMD) have been demonstrated as effective seismic resistant dampers. However, theoretical study on energy dissipation or energy harvesting of the TVMD has rarely been investigated, particularly, whether or not its optimal passive vibration control and energy dissipation maximization are consistent remains questionable. Here, from the theoretical perspective, we present an analysis of energy dissipation or energy harvesting of the TVMD in terms of damping power or output power, respectively. We derive the closed-form solutions of the average damping power of a single-degree-of-freedom (SDOF) structure-TVMD system under white-noise base excitations or seismic excitations modeled by the Kanai-Tajimi spectra, which is verified against the Monte Carlo simulations. Based on the closed-form solutions, the influences of the TVMD parameters, site conditions, and structural dynamic characteristics on the average damping power are analyzed via a parametric study. Theoretical results indicate that structural damping, site condition, structural period, frequency ratio, and inertance-to-mass ratio have a significant impact on the damping power or dissipated energy. In addition, the TVMD dissipates much more energy at a soft-soil site than at a stiff-soil site. At a stiff-soil site, the TVMD dissipates more energy for a short-period structure than for a long-period structure, however, at a soft-soil site, the law is the opposite. The study also presents the theoretical upper bound of the output power of an energy-harvesting TVMD. Particularly, results also illustrate that the maximization of TVMD energy dissipation is not consistent with the optimal passive vibration control. This study may shed light on the TVMD studies for seismic response control or energy harvesting purposes in the years to come.