Enhanced resonance transmission of acoustic waves based on asymmetric excitation of Lamb waves in phononic crystals with wedges-like structures

Abstract

In this paper, enhanced resonance transmission of acoustic waves with good performance is demonstrated in two-dimensional phononic crystals with wedges-like structures. The enhanced acoustic transmission originates from the excitation of asymmetric Lamb modes. The local resonances in the wedges-like structures play a vital important role in the excitation of asymmetric Lamb modes and promote the strong in-phase coupling of the flexural motions on the upper and lower plates of the liquid cavity, which leads to enhanced resonance transmission with high transmission ratio and narrow full width at half maximum. The enhanced transmission spectra for different liquids filled are also studied. Optimization of the liquid cavity geometry is further performed to improve the performance of the enhanced resonance transmission peaks. The proposed acoustic system has potential applications in tunable filtering and sensing applications. © 2014 AIP Publishing LLC.