Bandgap merging and widening of elastic metamaterial with heterogeneous resonator

Abstract

Much effort has been devoted to exploring broad bandgap in low frequency with limited mass by various structural designs of elastic metamaterials (EMs). In this paper, a heterogeneous resonator configuration in 1-D dissipative lattice mass system without additional increase of mass and coupling complexity is presented to generate multiple bandgaps. Special attention is focused on the effect of parameters control to merge the multiple bandgaps, and the analytical expression of parameters setting is obtained for broad bandgap merging. Specifically, the merging of all bandgaps in EMs with two heterogeneous resonators achieves 30% lower and 135% wider bandgap than that of classical local resonance (LR) EMs with the same mass ratio and stiffness ratio, while the merging of three LR bandgaps in EMs with three heterogeneous resonators is 20% lower and 63% wider. The relative movements of masses in the unit cell at different frequencies are depicted to reveal the working mechanism. The effect of damping factor on broadening vibration attenuation regime is studied. Finally, the vibration transmission properties of finite system with heterogeneous resonators, mass graded resonators and mass detuning resonators are compared to ensure the broad vibration attenuation range. This work could be beneficial for the design of vibration attenuation application in industry.

Recent advances and promise of MXene-based composites as electrode materials for sodium-ion and potassium-ion batteries

“…By incorporating external materials into the space between multiple MXene layers or edges, the surface area of the resulting composite tends to be significantly enhanced. 76 For instance, the CoNiO 2 / Ti 3 C 2 T x composite exhibits a bigger surface area (41 m 2 g −1 ) in contrast to Ti 3 C 2 T x alone (14 m 2 g −1 ). 77 Moreover, the composite displays a mesoporous nature with pore sizes ranging from 2 to 5 nm.…”

A brief review of metamaterials for opening low-frequency band gaps

“…Consequently, the wave manipulation in the low-frequency range is challengeable for the LR metamaterial. In the ordinary way, the major approaches used to broaden the low-frequency bandwidth include devising multi-degreeof-freedom resonator [96][97][98][99][100][101] , introducing an inerter into the local resonator [102][103] , establishing coupling between different resonators [104][105][106][107][108] , devising the graded local resonator by varying the mass and/or the stiffness of the resonator regularly [83,[109][110] , and loading axial forces on the primary structure [111] . Although these efforts belong to passive approaches, they have achieved an improvement of broadening the bandwidth of the low-frequency band gap.…”

Low frequency broadband bandgaps in elastic metamaterials with two-stage inertial amplification and elastic foundations

“…To better realize the purpose of low frequency broadband elastic waves regulation, a current research of EMs mainly focus on how to widen the low frequency bandgaps. Researchers attempted to merge multiple bandgaps in various ways to obtain wider bandgaps, respectively proposing EMs containing multi-resonators [17][18][19][20][21][22], EMs with damping elements introduced [23,24], and EMs that can accurately couple Bragg scattering bandgaps with LR bandgaps [25,26]. Moreover, there are also studies on broadening the bandgaps by introducing nonlinear elements [27][28][29][30].…”