FROM MEMBRANE-TYPE TO PLATE-TYPE ACOUSTIC METAMATERIALS: A LARGE-SCALE DESIGN FOR CABIN NOISE CONTROL

Abstract

To date, low-frequency cabin noise remains an issue in transport systems despite the range of noise control practices. A viable solution is membrane-type acoustic metamaterial. Since most studies were limited to small-scale specimens, it is imperative to explore them at a larger scale in view of industrial applications. During the assembly process of the large-scale design, the membrane and the platelets posed manufacturing challenges. Hence, the plate-type acoustic metamaterial was proposed. It was studied at small-scale and later showed that they could be scaled and modularly combined at large-scale. From the comparison with commercial noise barriers and evaluation in different noise environments, the design was shown to be viable for environmental noise control especially at low frequencies. Being only a proof-of-concept, the design still has room for improvement, leading to a design that is practical as an alternative solution for cabin noise control in transport systems.