Effects of Poisson’s ratio on the band gaps and defect states in two-dimensional vacuum/solid porous phononic crystals

Complete bandgaps in three-dimensional holey phononic crystals with helmholtz resonators

“…The bandgaps are found to be determined by several factors including material [3,4] and geometry parameters [5]. Particularly, careful design of structural topology may produce novel PCs with large bandgaps.…”

Bandgaps and directional propagation of elastic waves in 2D square zigzag lattice structures

“…In recent years, many works have been devoted to the study of PCs with periodic holes [3][4][5][6][7][8][9][10][11][12], the bandgaps of which are mainly determined by the geometry parameters. The cross section of the holes may be either convex [3][4][5][6][9][10][11] or non-convex (e.g.…”

“…The cross section of the holes may be either convex [3][4][5][6][9][10][11] or non-convex (e.g. cross-like [7]).…”

“…A system composed of large lumps connected by small connectors is easy to generate complete bandgaps due to the local resonances of the lumps. Such systems can be obtained by etching cross-like holes, circular holes, or rotated square holes in the matrix [3,5,[7][8][9]12]. The porosity (i.e.…”

“…the filling fraction of the vacuum part), f, of such systems generally has some intermediate values, and the porosity range for the existence of the bandgaps is small. Other systems without large lumps can hardly exhibit complete bandgaps [4], especially in the low frequency range [6,9,11]. For lattice structures with extremely high porosity (f →1) [13][14][15][16][17][18][19], which are widely used as stand-along structural components, narrow complete bandgaps exist for particular lattice forms and/or when the slenderness ratio of the beam is extremely big [15].…”