Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Wave propagation in a rainbow metamaterial beam
Submission Author:
Fábio Oliveira , RN , Brazil
Co-Authors:
Fábio Oliveira, Jose Maria Campos dos Santos
Presenter: Fábio Oliveira
doi://10.26678/ABCM.COBEM2021.COB2021-2332
Abstract
Metamaterials and phononic crystals (PCs) are broadly investigated for noise and vibration attenuation due to the stopbands generated by local resonance or Bragg effect, respectively. However, metamaterials and PCs application are limited by the stopband widths. The recently established Rainbow metamaterials, consisting of a periodic graded arrays of resonators, are opening new possibilities to broadband control of propagation of mechanical waves,and to generate wider stopbands than periodic structures. They are based on the rainbow trapping phenomena,which separates different frequency wave components and trap them in different positionsin space. By modeling the elastic metamaterials to be gradient in the unitcell distribution, robust elastic dispersion can beachieved and wave speed can be modulated to slow down to zero,and trapped in separate positions of space. Based on this approach, a rainbow metamaterial composed by a graded array of resonant beams attached transversally to a host longitudinal beam is proposed in the present study. To demonstrate the Rainbow effects, a conventional periodic metamaterial and an aperiodic rainbow metamaterial are investigated. Both metamaterial designs are modeled by the Spectral Element (SE) method and the Finite Element(FE) method. The simulated results are compared to each other and the results showed that the aperiodic Rainbow metamaterial beam has extended stopbands compared with the periodic one. Others results related to the Rainbow effects, like slowing down the elastic waves are also presented.
Keywords
Rainbow Metamaterial, Phononic Crystals, Stopband, spectral element, finite element
