An Inerter-Based Dynamic Vibration Absorber With Concurrently Enhanced Energy Harvesting and Motion Control Performances Under Broadband Stochastic Excitation Via Inertance Amplification

This paper examines the performance of a regenerative dynamic vibration absorber, dubbed energy harvesting-enabled tuned mass-damper-inerter (EH-TMDI), for simultaneous vibration suppression and energy harvesting in white noise excited damped linear primary structures. Single-degree-of-freedom (SDOF) structures under force and base excitations are studied as well as multi-degree-of-freedom (MDOF) structures under correlated random forces. The EH-TMDI includes an electromagnetic motor (EM), assumed to behave as a shunt damper, sandwiched between a secondary mass and an inerter element connected in series. The latter element resists relative acceleration at its ends through a constant termed inertance known to be readily scalable in actual inerter device implementations. In this regard, attention is herein focused on gauging the available energy for harvesting at the EM and the displacement variance of the primary structure as the inertance increases through comprehensive parametric investigations. This is supported by adopting simplified inertance-dependent tuning formulae for the EH-TMDI stiffness and damping properties and deriving in closed-form the response of white-noise excited EH-TMDI-equipped SDOF and MDOF systems through linear random vibration analyses. It is found that lightweight EH-TMDIs, having 1% the mass of the primary structure, achieve improved vibration suppression and energy harvesting performance as inertance amplifies. For SDOF structures with grounded inerter, the rate of improvement is higher as the inherent structural damping reduces and the EM shunt damping increases. For MDOF structures with non-grounded inerter, improvement rate is higher as the primary structure flexibility between the two EH-TMDI attachment points increases.