A lightweight multilayer honeycomb membrane-type acoustic metamaterial

This paper proposed a type of lightweight multilayer honeycomb membrane-type acoustic metamaterials (AMs) and the transmission loss is studied experimentally. It is demonstrated that lightweight honeycomb sandwich panel AMs can break the mass law and obtain the great sound transmission loss at a light-weight. The mass per cell area of the metamaterial structure has 0.29 kg/m(2) only and the total thickness of the structure is 4.2 mm, but the average sound transmission loss (STL) can achieve 17 dB. Experimental results from the impedance tube are presented to validate the conclusion and show that the STL peak frequency can be tuned to specific values by varying the combination of cell structures and membrane properties. (C) 2020 Elsevier Ltd. All rights reserved.