Investigation of complete bandgaps in a piezoelectric slab covered with periodically structured coatings

Ultrasonics. 2016 Feb:65:268-76. doi: 10.1016/j.ultras.2015.09.015. Epub 2015 Sep 28.

Abstract

The propagation of elastic waves in a piezoelectric slab covered with periodically structured coatings or the so-called stubbed phononic crystal slab is investigated. Four different models are selected and the effects of distribution forms and geometrical parameters of the structured coatings on complete bandgaps are discussed. The phononic crystal slab with symmetric coatings can generate wider complete bandgaps while that with asymmetric coatings is favorable for the generation of multi-bandgaps. The complete bandgaps, which are induced by locally resonant effects, change significantly as the geometry of the coatings changes. Moreover, the piezoelectric effects benefit the opening of the complete bandgaps.

Keywords: Bandgap; Elastic wave; Phononic crystal; Piezoelectric effect.