Large acoustic band gaps created by rotating square rods in two-dimensional periodic composites

• Published in: Journal of physics. D, Applied physics Vol. 36; no. 1; pp. L15 - L17
• Main Authors: Li, Xiaoling, Wu, Fugen, Hu, Hefei, Zhong, Shao, Liu, Youyan
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 07.01.2003; Institute of Physics
• Subjects: Acoustical properties of solids; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Mechanical and acoustical properties of condensed matter; Physics; Two-dimensional systems; Phononic crystal; Wave equations; Theoretical study; Fill factor; Energy gap; Composite materials; Acoustic properties; Angular variation; Square lattices; Rotation angle; Acoustic waves; Periodic structures
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/36/1/104

Effects of orientations of square rods on the acoustic band gaps in 2D periodic arrays of rigid solid rods embedded in air are studied. The acoustic band gaps will be opened and enlarged greatly by increasing the rotation angle. For any filling fraction F, the maximum acoustic band gaps appear at the same rotation angle theta = 45 deg for the cases of F not greater than 0.50; otherwise they will appear at different limit values theta-c and the largest band gap is achieved at a filling fraction of about F = 0.85. This gap-tuning effect will be stronger with an increase in filling fraction. This tuning mechanism of band gap suggests a new way to design band gaps of 2D phononic crystals.