Structural acoustics : deterministic and random phenomena

✍ Scribed by Joshua E Greenspon

• Publisher: Taylor & Francis
• Year: 2011
• Tongue: English
• Leaves: 290
• Category: Library

✦ Synopsis

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.

✦ Table of Contents

Content: 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