Evolution of Low-Frequency Band Gaps Using X-Shapes and Single-Sided Stubbed Phononic Crystals

Abstract

In this work, the evolution of dispersion relations of 2D asymmetric phononic crystals in the low-frequency range is introduced and discussed. Two phononic crystal structures are proposed and calculated using Finite Element method. The first one is a thin plate from PDMS with a circular one-side stubbed from tungsten and the other is a thin plate in the X-shape from rubber and tungsten. The effects of some parameters such as stub height and diameter on the phononic band gap value are studied. Low-frequency band gaps can be found in both structures with frequencies corresponding to the audible sound frequency range. The symmetry and shape of the stub has a remarkable influence on the band structures. Where, the proposed one-side stubbed exhibits a phononic band gap in a lower frequency range compared with the published studies about the double side stubbed. Furthermore, with the same thickness value the band gap value was reduced in the X-shape phononic stub compared with the one-side stubbed. These results may be useful for the low-frequency and noise suppression devices.