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DINAME2019
DINAME2019
Flexural Wave Band Gaps in Phononic Crystal Thick Plates with Defects
Submission Author:
Edson Jansen Pedrosa de Miranda Junior , MA
Co-Authors:
Edson Jansen Pedrosa de Miranda Junior, Jose Maria Campos dos Santos
Presenter: Edson Jansen Pedrosa de Miranda Junior
doi://10.26678/ABCM.DINAME2019.DIN2019-0002
Abstract
Much attention has been paid to mechanical wave propagation in phononic crystals. Phononic crystals are artificial composites consisting of a periodic array of inclusions embedded in a matrix. Due to its periodicity, Bragg-type band gaps are opened up and there are no propagating mechanical waves in these ranges of frequency. There are only evanescent waves in these ranges of frequency. We investigate the band structure of flexural waves propagating in an elastic phononic crystal thick plate with defects. We consider point defect and straight, bending and branching linear defects. The classical Mindlin-Reissner theory of thick plates is assumed. The phononic crystal thick plate consists of an epoxy matrix with Al2O3 inclusions in a square lattice. We also study the influence of inclusion geometry – circular, hollow circular, square and rotated square. The improved plane wave expansion method with supercell technique is used to calculate the phononic band structure. Three defect bands are created when the radius of the point defect becomes close to zero. The straight linear defect can be applied as high efficiency waveguide, whereas bending and branching linear defects act as waveguides or filters depending on the range of frequency.
Keywords
phononic crystal, Mindlin-Reissner theory, Bragg-type band gaps, improved plane wave expansion, supercell technique, waveguide, Filter
