An Approximate Estimation Method for Transmission Loss Peak Frequency of Membrane-Type Acoustic Metamaterials

<div class="section abstract"><div class="htmlview paragraph">Membrane-type acoustic metamaterials consist of a tensioned membrane fixed on the frame and an additional mass attached to the membrane. The sound insulation performance of membrane-type acoustic metamaterials is much better than the acoustic mass law predictions at transmission loss (TL) peak frequencies. In this paper, an equivalent mechanical model of membrane-type metamaterials is established. Through the vibration analysis of the membrane with tensile force as the main elastic restoring force, an approximate estimation method of the TL peak frequency of Membrane-type acoustic metamaterials is proposed, the effects of membrane tension, membrane size, mass and size of additional mass on the peak frequency of TL were analyzed quantitatively. The COMSOL software was used to establish a finite element analysis model and calculate the TL curve of the metamaterial at a frequency of 100-1600 Hz. At the same time, the impedance tube was used to conduct corresponding sound insulation experiments to verify the authenticity of the finite element calculation. The results show that the method can effectively predict the TL peak frequency of the metamaterials, and thus can accurately manipulate the sound insulation frequency band of the metamaterial. Finally, the sound insulation performance of structures in which metamaterials and porous materials are stacked in series and which different configuration metamaterials stacked in series are studied. This paper can provide some useful design references for practical engineering application of membrane-type acoustic metamaterials.</div></div>