Control of the elastic wave bandgaps in two-dimensional piezoelectric periodic structures

Theoretical studies are presented for the band structures of bulk waves in a two-dimensional composite structure consisting of rectangular piezoelectric ceramics placed periodically in an epoxy substrate. The dependences of the widths and starting frequencies of the first bandgaps (FBGs) on the filling fraction and the ratio of length to width of the embedded section are calculated for different polarized directions of the piezoelectric ceramics and different phononic structures. Our research shows that the FBG depend strongly on the polarized directions, the phononic structures, the filling fraction and the ratio of length to width, respectively. Therefore, one can control the FBG in engineering according to need by choosing these parameters of the system.