Complete low-frequency bandgap in a two-dimensional phononic crystal with spindle-shaped inclusions
Wang Ting1, 2, †, , Wang Hui2, Sheng Mei-Ping1, Qin Qing-Hua2
       

(a) Dispersion relation of the 2D PC with a = 30 mm, b = 18 mm, c = 16 mm, and d = 11 mm. (b) Comparison between the dispersion relation along the Γ–X direction and the transmission spectrum of the finite periodic structure with 16 unit cells.