Structural Acoustics

Dr. Greenspon received his Bachelor's, Master's, and Doctoral degrees from The Johns Hopkins University. While studying for his doctoral degree, he also taught Applied Mechanics for several years at the University. Upon completion of his course work, he was employed by the David Taylor Model Basin to do studies on ship vibrations. He completed the original research for his doctoral thesis in vibrations of thick cylindrical shells. He subsequently worked for the Martin Marietta Corporation doing research in panel flutter. He established a consultancy firm-JG Engineering Research Associates-and continued doing research under contract to the United States Army and Navy, in the areas of vibrations, sound radiation, and structures subject to blast and fragmentation. Dr. Greenspon was awarded the Silver Medal in Engineering Acoustics by The Acoustical Society of America for the solution of underwater radiation and scattering problems. He also served as an Associate Editor of the Journal of the Acoustical Society of America for 20 years. He was a member of the Acoustical Society of America, the American Society of Mechanical Engineers, the Society of Naval Architects and Marine Engineers, and the American Institute of Aeronautics and Astronautics. Dr. Greenspon passed away in February 2011, a few months before the publication of this book.

DETERMINISTIC PHENOMENA


General Overview of the Book
Introduction
Background
Overview of Random Structural Acoustics
Overview of Methods and Applications
Comparison of Methods Used in the Recent Literature
Applications
References


Fundamentals of Acoustics and Structural Acoustics
Introduction
Physical Phenomena in Linear Acoustics
Basic Assumptions and Equations in Linear Acoustics
Intensity and Energy
Free Sound Propagation
Sound Propagation with Obstacles
Free and Confined Waves
Sound Radiation and Vibration
Coupling of Structure/Medium (Interactions)
References
Glossary


Approximations for Added Mass and Radiation Damping
Definitions
References


Fundamentals of Structures and Analysis of Beams
Fundamentals of Structures
Beams
Plates
Shells
Three-Dimensional Variable Bodies
Analysis of Beams
Computer Programs
References


Unstiffened, Stiffened, Sandwich, and Composite Plates
Introduction
Unstiffened Plates
Rectangular Plates
Addition of Water Loading
Proposed Design Procedure for Simply Supported or Clamped Rectangular Plates under Uniform Impulsive Pressure
Cross-Stiffened and Sandwich Plates
Calculation of the Characteristics of Stiffened and Sandwich Plates
Composite Plates
Plate Applications
References


A Simplified Procedure for Built-up Structures
General Considerations
Potential Energy and Stiffness Coefficients
Equations of Motion and Basic Matrix
Effect of Fluid
Modal Impedances
Calculation of the Green's Function
Potential Energy of Stretching and Shearing
Potential Energy of Bending and Twisting
Stiffness Coefficients
Example Calculations
References


Sound Patterns from Cylindrical Shells
Introduction
Basic Equations
General Equations for Shell Vibrating in Fluid and Containing Fluid
Frequencies and Mode Shapes
Effect of External or Internal Pressure on Natural Frequency
Relation to Buckling
Forced Vibration
Description of the Computer Program
Far Field Patterns for a Representative Case
References


Analysis of Three-Dimensional Media with Variable Properties
Introduction
Physical Characteristics of the Mathematical Model
Differential Equations of the Complex Medium
Approximate Solution
Solution for Nonhomogeneous Systems
References


RANDOM PHENOMENA


Linear Systems Equations
Impulse Response
Frequency Response Function
Statistics of the Response
Important Quantities Derivable from the Cross Spectrum
The Cross Spectrum in Terms of Fourier Transforms
The Conceptual Meaning of Cross Correlation, Cross Spectrum, and Coherence
References


Statistical Acoustics
Physical Concept of Transfer Function
Response in Terms of Green's Functions
Statistical Differential Equations Governing the Sound Field
References


Statistics of Structures
Integral Relation for the Response
Computation of the Response in Terms of Modes
Coupled Structural Acoustic Systems
References


Random Radiation from Cylindrical Structures
Directivity Patterns
Multipole Expansion
Random Loading and Response
Computer Programs
References


Applications of Statistical Acoustics to Near Field-Far Field Problems
The Near Field-Far Field Problem
Parrent's Solution for the Plane
Other Applications of the Parrent Equation
Solution Using a Single Integration with Known Coherence
Determination of Far Field from Near Field Autospectrum Alone and the Inverse Far Field-Near Field Problem
Simplification of Equations for Plane Waves
Methods for Computing Far Field from Near Field Acceleration
Application to Prediction of Radiation
Inverse Method Calculation: Development of the Field in
Terms of Point Sources
Point Force Calculations
References


Scale Models of Random Loading and Response
Approximate Formulation of the Modeling Laws
Damping
More General Formulation of Modeling Laws
Some General Considerations in Modeling
References


Index