Numerical analysis of acoustic band gaps in two-dimensional periodic materials

Using the plane-wave expansion (PWE) method , the band gaps of the two-dimension phononic crystals composed of square, triangle and honeyeomb arrays aluminum cylinders in the air are calculated numerically. The band structures of three lattices were compared and analyzed,It is concluded that the band-gap of honeycomb lattices is located at lower frequency fields,compared with square and triangle lattices. When the filling fraction is between 0. 091 and 0. 604 6,the honeycomb lattices have larger band gaps and gain an advantage over square and triangle lattices. In addition,the gap map is introduced to illustrate the influences of filling fraction on the number, the relative width and the limit frequency of the band-gap.