Underwater Acoustics Evaluation of Glass Fiber – Polyurethane Sandwich Composite

Abstract

This article presents underwater acoustics evaluation of glass fiber – polyurethane sandwich composite which is useful for ship materials. The composite consists of two main functional laminations namely structural and acoustical lamination. The structural lamination is constructed from polyester and polyethylene fibers while the polyurethane is potential for acoustical lamination. The fabrication involves vacuum bagging and conventional hydraulic methods. The materials will be treated in both with and without immersion in sea water. The immersion process takes time about 72 hours. The properties of acoustics for each materials generally have high insertion loss (maximum found 25 dB), but some of them can reach low insertion loss (below 5 dB). The optimization of combination between structural and acoustic materials is promising to be investigated in near future to achieve the optimum properties of materials in terms of sound transparency.