Sound insulation properties of membrane-type acoustic metamaterials with petal-like split rings

Membrane-type acoustic metamaterials (MAMs) are lightweight and flimsy materials with excellent low-frequency insulation performance, which breaks the limitations of the traditional mass law and provides a new idea for noise reduction in the low-frequency range. To further broaden the sound insulation bandwidth on the premise of lightweight design, a novel MAM with petal-like rings is proposed, and the parametric studies on the structural parameters of split rings are carried out in this paper. By combining the finite element model simulation and impedance tube test, the effectiveness of the proposed structure and the correctness of the numerical simulation are validated. Moreover, the sound transmission loss curves and modal shapes of four different structures are computed and analyzed to clarify the insulation mechanism of the novel structure. Finally, the width, the center angle, the centroid position, and the weight of the split rings in the novel structure are parametrically analyzed to figure out the regulation rules of the sound insulation characteristics.