Theoretical Acoustics of Underwater Structures

The following sections are included:

• CONTENTS

• PREFACE

• ACKNOWLEDGEMENTS

The acoustic characteristics of a ship, building or machine are likely to be but one of a number of sometimes conflicting requirements of an engineering or building project. Nonetheless, because it is likely to retain some importance, there will be some acoustic objective to be achieved subject to various constraints such as cost and operational requirements. Generally, theoretical modelling as well as experimental testing should be built into an acoustic design procedure, the former being particularly valuable because it increases the range of options which can be assessed while at the same time helping to reduce the chances of introducing unwanted acoustic features, particularly in structures of novel design and/or new materials. It is the role of an acoustician to provide theoretical modelling support, either for paper assessment studies or for experimentally based structural and materials research programmes. To effectively provide this support it is desirable for an analyst to have access to a wide range of theoretical tools, in both textbook and software form, and to be experienced in their use. These tools can then be used as basic building blocks for solving more complex acoustical problems, and can also be used as examples of how new building blocks can be developed. Thus, herein are provided many of the basic building blocks for modelling the dynamics and acoustics of underwater elastic structures, and it will be found that many of the models described can also find a wide range of applicability in the field of architectural acoustics…

The following sections are included:

• Fourier Series

• Fourier Transforms

• Delta Functions

• Vector and Scalar Identities

• Integral Theorems

• Bessel Functions

• Spherical Bessel Functions

• Legendre Functions

• Stationary Phase

• Matrices

• Numerical Integration

• References and Additional Reading

The following sections are included:

• Time-Harmonic Response

• Transient Response

• Time-Harmonic Power Flow

• References and Additional Reading

The following sections are included:

• Differential Equation

• Plane Wave Solutions

• Green's Function in Cartesian Coordinates

• Green's Function in Cylindrical Coordinates

• Green's Function in Spherical Coordinates

• Arbitrary Source Distribution

• Arbitrary Boundaries

• Helmholtz Integral Equation

• References and Additional Reading

The following sections are included:

• Planar Surface

• Spherical Surface

• Cylindrical Surface

• Axisymmetric Slender Body

• Monopole in Axisymmetric Channel

• References and Additional Reading

The following sections are included:

• Variational Principle

• Finite Element Discretization

• Acoustic Finite Elements

• Radiation Boundary Condition

• Sources of Sound

• Axisymmetric Elements

• References and Additional Reading

The following sections are included:

• Strain and Stress

• Isotropic Displacement Equations

• Finite Element Variational Principle

• Fluid Constants

• Isotropic Elastic Constants

• Anisotropic Solid

• Unidirectional Fibre Reinforcement

• Thin Layered Composite

• Local to Global Transformation

• Effective Constants of Symmetric Stack

• References and Additional Reading

The following sections are included:

• Equations of Motion

• Mechanical Excitation

• Acoustical Excitation

• References and Additional Reading

The following sections are included:

• Equations of Motion

• Mechanical Excitation

• Monopole Excitation

• Plane Wave Excitation

• Transient Sound Radiation

• Frame and Bulkhead Stiffened Plate

• Orthogonally Stiffened Plate

• Plate with Point Attachments

• Parallel Plates with Attachments

• Plate with Periodic Resonators

• References and Additional Reading

The following sections are included:

• Equations of Isotropic Shell

• Equations of Anisotropic Shell

• Mechanical Excitation

• Monopole Excitation

• Plane Wave Excitation

• Periodic Rib Stiffening

• Axisymmetric Attachments

• Fluid Coating

• References and Additional Reading

The following sections are included:

• Introduction

• Acoustic Fluid Layer

• Isotropic Elastic Layer

• Viscous Fluid Layer

• Assembly of Elements

• Mechanical Excitation

• Acoustical Excitation

• Numerical Examples

• References and Additional Reading

The following sections are included:

• Introduction

• Acoustic Fluid Layer

• Isotropic Elastic Layer

• Orthotropic Elastic Layer

• Viscous Fluid Layer

• Assembly of Elements

• Mechanical Excitation

• Monopole Excitation

• Plane Wave Excitation

• Low Frequency Sound Propagation

• References and Additional Reading

The following sections are included:

• Introduction

• Acoustic Fluid Layer

• Isotropic Elastic Layer

• Orthotropic Elastic Layer

• Viscous Fluid Layer

• Assembly of Elements

• Mechanical Excitation

• Monopole Excitation

• Plane Wave Excitation

• References and Additional Reading

The following sections are included:

• Isotropic Thin Cylinder

• Point Force Excitation

• Plane Wave Excitation

• Anisotropic Layered Cylinder

• References and Additional Reading

The following sections are included:

• Introduction

• Fourier Series

• Helmholtz Integral Equation

• Far Field Acoustics

• Fluid–Structure Equations

• Conical Shell Finite Element

• Axisymmetric Solid Finite Element

• System Dynamic Stiffness

• Numerical Examples

• References and Additional Reading

The following sections are included:

• LIST OF COMMONLY OCCURRING SYMBOLS

• INDEX