Metamaterial Beam with Bistable and Monostable-Hardening Attachments for Broad-Band Vibration Attenuation and Energy Harvesting

Dynamic local resonating (LR) metastructures possess the ability to suppress the propagation of vibrations within a specific frequency range known as a bandgap. However, metastructures with pure linear local resonators have limited bandgap size and inevitably form new resonating peaks close to the bandgap. This paper proposes a metastructure that features alternatively arranged oscillators with bistable and monostable cubic hardening nonlinearities, as well as electromechanical coupling. This design effectively suppresses high-amplitude resonating transmission peaks near the bandgap and maintains the bandgap at high excitation levels. In addition, it can create a broad bandwidth with high power output, which can be applied as a practical source of electrical energy, thereby forming a well-balanced and performance-enhanced dual-functional metastructure for vibration suppression and energy harvesting. The proposed metastructure is established and calculated using a distributed-parameter model. The influence of nonlinearity stiffness and electrical-mechanical coupling index are investigated. Results show that enhanced performance of both vibration attenuation and energy harvesting can be realized with the proposed metastructure at a large range of excitation level. The parametric results offer a valuable reference for the development of dual-functional metastructures for simultaneous vibration suppression and energy harvesting.