Wave focsuing in phononic thin plates

Author

Tsung-Tsong Wu ; Chun-Wei Chen

Author_Institution

Inst. of Appl. Mech., Nat. Taiwan Univ., Taipei, Taiwan

fYear

2012

fDate

7-10 Oct. 2012

Firstpage

1

Lastpage

4

Abstract

This paper aims at investigating the focusing of the lowest anti-symmetric Lamb wave (A₀ mode) in both the GRIN and negative refraction (NR) based PC thin plates. Numerical results demonstrated that Lamb wave can be compressed efficiently in the GRIN PC plate and forms a focusing region along the centre line of the GRIN PC. The amplitude at the focusing region can be doubled approximately, while the bandwidth can be as large as 33%. For the case of the flat PC lens in a thin plate, numerical results showed the existence of the NR-based focusing which is similar to that of the bulk wave case. Simulation results showed that the full widths at half maximum (FWHM) of the focal spots of both the GRIN PC plate and the flat PC lens are around the order of one wavelength.

Keywords

gradient index optics; lenses; metamaterials; phononic crystals; surface acoustic waves; GRIN phononic thin plate; flat phononic lens; focal spots; focusing region; lowest antisymmetric Lamb wave focusing; negative refraction based phononic thin plate; negative refraction-based focusing; Acoustic waves; Aluminum; Focusing; Lattices; Lenses; Numerical simulation; Sun;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium (IUS), 2012 IEEE International

Conference_Location

Dresden

ISSN

1948-5719

Print_ISBN

978-1-4673-4561-3

Type

conf

DOI

10.1109/ULTSYM.2012.0286

Filename

6562078