Can we unify vibration control and energy harvesting objectives in energy regenerative tuned mass dampers?

As an emerging concept, energy-regenerative tuned mass dampers (ERTMDs) have recently been proposed to perform vibration control and energy harvesting functions simultaneously. This study aims to answer a fundamental question whether these two intended functions are consistent in an ERTMD. The closed-form solutions for the optimal parameters of an ERTMD installed in a damped structure are derived first, wherein the optimization objectives, namely, minimize the kinetic energy of the controlled structure and maximize the harvested power from ERTMDs, are both considered. Results reveal that the optimal parameters for the two scenarios are identical and thus prove that the two performance objectives can be optimized simultaneously in an ERTMD. The effects of mass ratios of ERTMDs are evaluated based on the derived analytical solution, and the results demonstrate that a large mass ratio benefits both vibration control and energy harvesting functions of ERTMDs under random excitations. The effectiveness and accuracy of the analytical solution are validated through a numerical case study. Numerical results also indicate that the interested power terms of ERTMDs are likely insensitive to the parameter detuning or the optimization criteria adopted.