A dual-mass delayed resonator: Extended operable frequency band, enhanced vibration control, and lightweight design

As an active vibration absorber, delayed resonators (DRs), driven by the feedback force following (delayed) past system states, can enable complete vibration suppression at a given frequency. Different from the classical single-mass DRs (SM-DRs), we propose a dual-mass DR (DM-DR), first aiming to extend the operable frequency band that is known to be limited by the stability issues arising from the feedback control scheme. This stems from the finding that the DM-DR can entail a broader inherent (passive) resonance bandwidth, making it easier to be ideally resonated within a broader bandwidth. Then, the frequency response of the primary is examined to seek enhanced vibration control performance. With the same amount of absorber mass deployed, comparisons regarding an example system show the advantages of the DM-DR over the SM-DR, including 43.4% resonance reduction in addition to 276% extension of the operable bandwidth when achieving complete vibration suppression. It also indicates that to achieve the same performance, the DM-DR requires much smaller absorber mass, thus enabling lightweight design. Finally, the absorber behaviors of the DM-DR are elucidated to guide practical implementation.