Band Gap and Waveguide Characteristics of Petal-Shaped Scatterer Phononic Crystals

Abstract

In this study, the Bragg petal-shaped scatterer (PS) phononic crystal (PnC) model is built to expand the width of band gap (BG). The BG characteristics of the PSPnC, square, circular, octagonal, and the "+" shaped scatterer PnC are compared using the finite element method (FEM). This study investigates the effects of the internal and external diameter ratio and the number of petals of single-layer petals, double-layer petals and the application of pre-deformation without changing their structure on the BG characteristics of PnCs for the transmission characteristics of supercell structures. Moreover, two different waveguides (WGs) are built with pre-deformed unit cells as the defects. As revealed by the results, the PSPnC exhibited better vibration isolation performance than PnCs with other shapes. More BGs will appear at a higher frequency with the decrease in the ratio of inner and outer diameter of petals and the increase in the number of petals. In addition, the double-layer PSPnC has high performance, and the dislocation arrangement of PS can enhance the vibration isolation performance of PSPnC. Furthermore, the WG structure is capable of guiding the energy, which provides a new insight into the establishment of the filter.