Study on Sound Insulation Performance of Membrane-Type Acoustic Metamaterials with Pendulum Arm

Membrane-type acoustic metamaterials have attracted attention for their good sound insulation. Inspired by the membrane-type acoustic metamaterial structure of cross pendulum arm three types of pendulum arm structures are proposed in this paper: cross-shaped pendulum arm plus eight-mass block, star-shaped pendulum arm plus four-mass block, and star-shaped pendulum arm plus eight-mass block. In order to compare the sound insulation performance of different structures, the low-frequency sound insulation mechanism of membrane-type acoustic metamaterials is analyzed, and the sound transmission loss of different structures is simulated according to the calculation formula. Through the sound transmission loss curve obtained by the simulation model, it is found that under the condition of the same mass distribution, the star-shaped pendulum arm has better sound insulation performance than the cross-shaped pendulum arm. In the case of the same pendulum arm, the sound insulation performance of the eight-mass evenly distributed block is better than that of the four-mass evenly distributed block. The sound insulation performance of the star-shaped pendulum arm plus the eight-mass block is the best among the three new models. The accuracy of the simulation method is verified by sound insulation experiments.