Fano-like resonance phenomena by flexural shell modes in sound transmission through two-dimensional periodic arrays of thin-walled hollow cylinders

摘要

It is shown that the n=2 and 3 flexural shell vibration modes of thin-walled hollow cylinders result in Fano-like resonant enhancement of sound wave transmission through or reflection from two-dimensional periodic arrays of these cylinders in air. The frequencies of the resonant modes are well described by the analytical theory of flexural (circumferential) modes of thin-walled hollow cylinders and are confirmed by finite-difference time-domain simulations. When the modes are located in the band gaps of the phononic crystal, an enhancement of the band-gap widths is produced by the additional restoring forces caused by the flexural shell deformations. Our conclusions provide an alternative method for the vibration control of airborne phononic crystals.