Band-gap property of a novel elastic metamaterial beam with X-shaped local resonators

A new type of the elastic metamaterial beam with X-shaped local resonators is designed and the vibration attenuation property of the proposed structure is investigated by the spectral element method (SEM). The novel X-shaped configuration is exploited for the structural nonlinear local resonators of the elastic metamaterial beam. The underlying mechanism is based on the unique function of the proposed X-shaped mechanism, that is, it can mitigate or amplify the stiffness of the linear spring due to the structural non-linearity. This behavior is utilized to design a novel elastic metamaterial beam with perfect adjustable band-gap property. Compared with the band-gaps of the elastic metamaterial beam with linear local resonators, those of the proposed elastic metamaterial beam can be adjusted to get lower or higher frequency band-gaps by the parametrical design. Numerical and experimental investigations are conducted to validate the advantageous features of the proposed elastic metamaterial beam. The results provide an efficient way to design novel elastic metamaterial beams with structural nonlinear local resonators to increase the adjustability of band-gaps and control the vibration or elastic wave propagation. (C) 2019 Elsevier Ltd. All rights reserved.