Greenspon Structural Acoustics

Deterministic and Random Phenomena
1. Auflage 2011
ISBN: 978-1-4398-3094-9
Verlag: Taylor & Francis
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 297 Seiten

From jet engine noise that generates vibrations in the structure of an aircraft, to the sound radiation from the hull of a ship or submarine that makes it identifiable, an understanding of structural acoustics is key in the design process in maritime, automotive, aerospace, and architectural engineering. Building on classic works in the field, Structural Acoustics: Deterministic and Random Phenomena presents fundamental concepts, relations, and simplified methods for calculating complex problems associated with vibrations and noise issues of automobiles, ships, submarines, and aircraft. This practical reference studies the response of structures and media that are coupled with a fluid and are under static, dynamic, and random loading.
Simplified solutions to complicated problems

Starting with a review of the fundamentals of acoustics and structural acoustics, the book discusses the response of the beams, plates, and shells that compose most built-up structures before providing methods for solving problems of built-up systems, including a procedure for computing the response of an elastic or viscoelastic media without resorting to a large computer program. Building on this analysis, the second section develops the analysis for random loading, which can also be applied to geophysical phenomena and viscoelastic media. Proceeding from the fundamental aspects of simple structures to more complicated cases with more involved loading, the book presents formulas and applications for random loading.
By providing a fundamental understanding of sound radiation in air and water, this book shows readers how to solve structural and acoustical problems. An important reference for those working in the area of acoustics and vibration analysis, it also includes computer programs for acoustical analysis available at www.crcpress.com.

Zielgruppe

Engineers who research and design automobiles, ships, submarines, and aircraft; physicists in vibrations and acoustics; graduate students in mechanical, aerospace, and maritime engineering.

Autoren/Hrsg.

Greenspon, Joshua E.

Fachgebiete

• Technische Wissenschaften Maschinenbau | Werkstoffkunde Technische Mechanik | Werkstoffkunde Statik, Dynamik, Kinetik, Kinematik
• Naturwissenschaften Physik Angewandte Physik
• Technische Wissenschaften Technik Allgemein Physik, Chemie für Ingenieure
• Naturwissenschaften Physik Mechanik Akustik, Schwingungsanalyse

Inhaltsverzeichnis

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

Über Autor(innen)

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.