Hybrid phononic crystal plates for lowering and widening acoustic band gaps

M Badreddine Assouar; Jia-Hong Sun; Fan-Shun Lin; Jin-Chen Hsu

doi:10.1016/j.ultras.2014.06.008

Hybrid phononic crystal plates for lowering and widening acoustic band gaps

Ultrasonics. 2014 Dec;54(8):2159-64. doi: 10.1016/j.ultras.2014.06.008. Epub 2014 Jun 19.

Authors

M Badreddine Assouar¹, Jia-Hong Sun², Fan-Shun Lin³, Jin-Chen Hsu⁴

Affiliations

¹ CNRS, Institut Jean Lamour, Vandoeuvre-lès-Nancy F-54506, France; University of Lorraine, Institut Jean Lamour, Boulevard des Aiguillettes, BP: 70239, Vandoeuvre-lès-Nancy 54506, France.
² Department of Mechanical Engineering, Chang Gung University, Kwei-Shan, Taoyuan, Taiwan.
³ Department of Mechanical Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin 64002, Taiwan.
⁴ Department of Mechanical Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin 64002, Taiwan. Electronic address: hsujc@yuntech.edu.tw.

PMID: 24996255
DOI: 10.1016/j.ultras.2014.06.008

Abstract

We propose hybrid phononic-crystal plates which are composed of periodic stepped pillars and periodic holes to lower and widen acoustic band gaps. The acoustic waves scattered simultaneously by the pillars and holes in a relevant frequency range can generate low and wide acoustic forbidden bands. We introduce an alternative double-sided arrangement of the periodic stepped pillars for an enlarged pillars' head diameter in the hybrid structure and optimize the hole diameter to further lower and widen the acoustic band gaps. The lowering and widening effects are simultaneously achieved by reducing the frequencies of locally resonant pillar modes and prohibiting suitable frequency bands of propagating plate modes.

Keywords: Acoustic band gap; Bragg scattering; Local resonance; Phononic crystal; Plate waves.