Modeling and Analysis of Phononic Crystal With Coupled Lanes for Enhanced Elastic Wave Attenuation

Phononic crystals and metamaterials have attractive potential in elastic wave attenuation and guiding over specific frequency ranges. Different from traditional phononic crystals/metamaterials consisting of identical unit cells, a phononic crystal with coupled lanes is reported in this article for enhanced elastic wave attenuation in the low-frequency regime. The proposed phononic crystal takes advantages of destructive interference mechanism. A finitely length phononic crystal plate consisting of coupled lanes is considered for conceptual verification. The coupled lanes are designed to split the incident elastic wave into separated parts with a phase difference to produce destructive interference. Theoretical modeling and finite element method (FEM) analysis are presented. It is illustrated that significant elastic wave attenuation is realized when the phase difference of elastic waves propagating through the coupled lanes approximates pi. Besides, multiple valleys in the transmission can be achieved in a broad frequency range with one at a frequency as low as 1.85 kHz with unit cells' width and length of 25 mm and ten unit cells in one lane.