A multi-bandgap metamaterial with multi-frequency resonators

Abstract

A 2D metamaterial cellular system inspired by lightweight honeycombs and spider webs is investigated. The hexagonal cells of the honeycomb act as hosting substructures for spider-web-like or cantilever resonators with added lumped masses which can vibrate, in principle, in any of the infinitely many modes. Contrary to traditional approaches utilizing discrete mass-spring resonators, here the infinite-dimensional (full spectrum) resonators are intentionally tailored to generate multiple, complete or incomplete, stop bands across which wave propagation is either totally or partially suppressed along preferential directions. The Plane Wave Expansion method is employed to obtain the dispersion curves and the bandgap sensitivity with respect to the design parameters. Experimental results based on laser scanning vibrometry corroborate the theoretical predictions and confirm the robustness of the stop band behavior with a wealth of results which pave the way towards suitable optimization strategies and a closer understanding of these formidable stop band cellular material systems.

Uncovering and Experimental Realization of Multimodal 3D Topological Metamaterials for Low‐Frequency and Multiband Elastic Wave Control

“…Furthermore, previous research has revealed that multimodal resonances can be harnessed to create multiple low‐frequency bandgaps in mechanical metamaterials. [ 52 , 58 , 59 ] In the proposed 3D topological metamaterial, the large mass ratio and relative compliance of the mesh‐like aluminum lattice structure facilitate the achievement of multiple low‐frequency out‐of‐plane and in‐plane translational and torsional resonances. This rich set of resonances opens opportunities for multi‐polarized and multiband responses in a low‐frequency regime.…”

Unusual nonlinear switching in branched carbon nanotube nanocomposites

“…The ability to tailor the softening and hardening response by adjusting the bCNT weight fraction can be leveraged to manufacture high-performance materials for the next generation of slender structures capable of withstanding large nonlinear deformations while dissipating significant amounts of energy without suffering damage or failure. In the realm of vibration control, the potential to manipulate the mechanical properties of the composite by varying the bCNT weight fraction can be utilized to create nonlinear metamaterials with secondary bandgaps arising from parametric and sub/super-harmonic resonance phenomena 30 . Additionally, the unusual switch from softening to hardening can be harnessed for the development of new generations of micro-sensors.…”