Directional propagation characteristics of flexural wave in two-dimensional periodic grid-like structures

The propagation characteristics of flexural waves in a two-dimensional (2D) periodic grid-like structure are analysed with the plane wave expansion method to yield phase constant surfaces, which can predict high directivity of flexural wave propagation for certain frequencies within pass bands. The prediction is validated through computation of the harmonic responses of a finite structure with 21 x 21 unit cells. The results can guide the design of 2D periodic grid-like structures where flexural waves at certain frequencies do not propagate in specified directions.