STRUCTURAL ACOUSTIC PHYSICS BASED MODELING OF CURVED COMPOSITE SHELLS

摘要

Understanding sound wave propagation through a curved shell geometry is essential for a wide variety of underwater applications. The objective of this study was to use physics-based modeling (PBM) to investigate wave propagations through curved shells that are subjected to acoustic excitation. An improved understanding of the absorption and reflection properties of materials, such as fiber-reinforced polymer (FRP) composites, will enhance the design methods for a variety of Navy products such as acoustic sensors, acoustic windows, and unmanned underwater vehicles. The research documented in this report investigates the reflection and transmission coefficients of both flat plates and curved shells for steel and composite materials. Results show that the finite element computational models accurately match analytical calculations, and that the composite material studied in this report has more desirable reflection and absorption properties than steel for typical Navy applications. This research also explores the use of coupled Eulerian-Lagrangian (CEL) and smoothed particle hydrodynamics (SPH) modeling approaches in place of the current, traditional Lagrangian approach. Unfortunately, these approaches were found to be unsuitable for the type of acoustic analyses performed throughout this research. However, results from the traditional Lagrangian approach confirmed the validity of current modeling techniques and allowed for the study of the acoustic properties of various geometries and materials. This can help drive future research on composite material applications and enhance design methods for future Navy products.