Elastic Wave Modulation in Hollow Metamaterial Beam With Acoustic Black Hole

Abstract

We propose and discuss the elastic wave attenuation of hollow metamaterial beam embedded acoustic black hole. More abundant physical phenomena are given by modal analysis, shows that the band gap of three-dimensional acoustic black hole metamaterial is different from two-dimensional one. Lateral flexural vibrations occurs and make the original first two-dimensional band gap be compressed, and the opening of first three-dimensional band gap are caused by coupling effect between the longitudinal and lateral flexural vibrations. Below 1200Hz, only two band gaps exist, the geometric parameter m1 and angle γ could affect the band structure a lot, while the effect of geometric parameter m0 is a little less. Mutual validation of transmission spectra of vibration test and finite element analysis calculation and band gaps, illustrating its validity of the structure design, corresponding results could stimulate the realizations of three-dimensional acoustic black hole structure, particularly paves the way for the bridge from the corresponding theory of low frequency vibration and noise reduction to the practical application.