Commercialization of metamaterial for industrial structure applications

Abstract

This thesis presents commercialization methods for applying acoustic metamaterial to industrial systems. Metamaterial is the artificial material with special wave propagation properties that do not exist in nature. So, it can be utilized in various fields according to their properties. This thesis focuses on the band gap of a Locally Resonant Metamaterial (LRM) that blocks wave propagation in a specific frequency band. LRM consists the resonators are periodically arranged in a unit structure, so that wave propagation is blocked in the resonant frequency band of the resonator. Since LRMs have significantly higher wave blocking performance than other treatments, various studies are being conducted in the field of acoustics/vibration. Despite the active research of LRM, there have been no examples of its application in the industrial field yet. In this thesis, three limitations to be improved for the commercialization of LRM are defined as follows. The first limitation is flexibility. Most industrial structures are composed of flat and curved surfaces, so LRM that can be applied to curved surfaces should be developed. This thesis tried to solve the limitation of flexibility by proposing a flexible LRM structure that can be attached to different curved surfaces without the need for redesign. The second limitation is the narrow band width. The frequency band of noise caused by an industrial structure is not limited to a single frequency band and is diverse. Therefore, it is required to design the broadband LRM targeting various frequency bands. In this thesis, broadband LRM concepts are introduced and their possibilities are verified. The last limitation is the mass productivity. In order to be commercialized, mass production of LRM must be possible. So far, examples of metamaterials that can be mass-produced have not been disclosed. In this thesis, the design of mass producible LRM is introduced and the process is presented. Finally, this thesis present a new LRM unit structure with the concept of integrating each of the improvements mentioned above and show the possibility of commercialization of metamaterials.