Structural Design and Performance Analysis of a Three-Dimensional Acoustic Metamaterial

A three-dimensional acoustic metamaterial consisting of frame, spherical attachment and membrane is designed, which has an extremely wide sound insulation band and a low sound insulation frequency. Finite element method is employed to study the influence of spherical attachment size, frame cross section size and membrane thickness on the forbidden band. Results show that within a certain range, as the radius of the attachment increases, the termination frequency and width of the first forbidden band increase. As the frame cross section size increases, the starting frequency of the first forbidden band increases. As the thickness of the membrane increases, the starting frequency of the first forbidden band does not change too much, and the termination frequency of the first forbidden band decreases sharply, and then tends to be flat.