A Study on the Acoustic Performance Design Technique of Underwater Acoustic Material

ABSTRACT The requirement of acoustic performance about underwater acoustic material which is used in un-derwater environment more increases. Underwater acoustic material was made by viscoelastic material such as a rubber and a polyurethane etc. In order to increase an acoustic performance, several kinds of inclusions were added to viscoelastic material. In this paper, acoustic modelling and analysis tech-niques were introduced and the acoustic characteristics of underwater acoustic material were studied. Echo reduction and transmission loss were calculated with volume fraction of inclusion in the material. Also the characteristic impedance and the input impedance of underwater acoustic material were obtained and effects on the echo reduction and transmission loss of material were discussed. * 1. 서 론 수중환경에서 음파의 반사 및 투과를 위해서 사용되는 수중 음향재료는 다양한 종류 및 형태로 제작되어 사용된다. 수중 음향재료는 주위 유체인 물과 임피던스를 유사하게 맞추기 위해서 주로 고무 또는 폴리우레탄 등의 점탄성 재료를 사용하여 제작되며 최적의 음향 성능을 발휘하기 위하여 기공 및 다양한 형태의 첨가재가 사용된다.Gaunaurd