Simultaneous low-frequency vibration suppression and energy harvesting using a metastructure with alternately combined nonlinear local resonators

This paper proposes a novel dual-functional nonlinear metastructure for amplitude-robust simultaneous vibration suppression and energy harvesting, consisting of combined bistable and monostable cubic-hardening nonlinear electromechanical resonators that are alternately arranged on a host structure. The proposed design can effectively achieve wide bandgap even at high acceleration levels, suppress the undesired resonance transmission peaks outside the bandgap that are deemed as inevitable troubles in conventional linear metastructures, and generate power across a broad bandwidth at low frequencies. It is shown experimentally that the fabricated nonlinear prototype suppresses the unwanted resonance peaks by up to 70.5% while widening the bandgap by 52%, compared to the linear counterpart. A distributed-parameter electromechanically coupled model is established to verify the experimental measurements. Analytical expressions for the dynamic and electrical responses are explicitly derived using the harmonic balance method, based on which the interplay between several key parameters and their influences on the performance of the system are investigated, including the cubic nonlinear stiffness, mass ratio, load resistance, and electromechanical coupling strength. The findings provide a valuable guideline for accurately assessing the dual capabilities and facilitate efficient optimization of the next-generation nonlinear metastructure system.