Vibrations and Acoustic Radiation of Thin Structures: Physical Basis, Theoretical Analysis and Numerical Methods

291 Pages·2008·3.49 MB·English

by  Paul J. T. Filippi

Vibrations and Acoustic
Radiation of Thin Structures
Physical Basis, Theoretical Analysis and Numerical Methods
Paul J.T. Filippi
Series Editor
Société Française d’Acoustique
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Vibrations and Acoustic Radiation of Thin Structures
This page intentionally left blank
Vibrations and Acoustic
Radiation of Thin Structures
Physical Basis, Theoretical Analysis and Numerical Methods
Paul J.T. Filippi
Series Editor
Société Française d’Acoustique
First published in Great Britain and the United States in 2008 by ISTE Ltd and John Wiley & Sons, Inc.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as
permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced,
stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers,
or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA.
Enquiries concerning reproduction outside these terms should be sent to the publishers at the
undermentioned address:
ISTE Ltd John Wiley & Sons, Inc.
27-37 St George’s Road 111 River Street
London SW19 4EU Hoboken, NJ 07030
UK USA
www.iste.co.uk www.wiley.com
© ISTE Ltd, 2008
The rights of Paul J.T. Filippi to be identified as the author of this work have been asserted by him in
accordance with the Copyright, Designs and Patents Act 1988.
Library of Congress Cataloging-in-Publication Data
Filippi, Paul J.T.
Vibrations and acoustic radiation of thin structures : physical basis, theoretical analysis and numerical
methods / Paul J.T. Filippi.
p. cm.
Includes bibliographical references and index.
ISBN 978-1-84821-056-1
1. Sound--Transmission. 2. Sound-waves. 3. Thin-walled structures--Vibration. 4. Radiation sources.
I. Title.
QC243.F56 2008
620.2--dc22
2008019708
British Library Cataloguing-in-Publication Data
A CIP record for this book is available from the British Library
ISBN: 978-1-84821-056-1
Printed and bound in Great Britain by CPI Antony Rowe Ltd, Chippenham, Wiltshire.
To my wife Dominique,
who inspires in all ways
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Contents
Preface 11
1 Equations Governing the Vibrations of Thin Structures 15
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.1.1 General Considerations on Thin Structures . . . . . . . 15
1.1.2 Overview of the Energy Method . . . . . . . . . . . . . 16
1.2 Thin Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.2.1 Plate with Constant Thickness . . . . . . . . . . . . . . 18
1.2.2 Plate with VariableThickness . . . . . . . . . . . . . . . 25
1.2.3 Boundary with an Angular Point . . . . . . . . . . . . . 27
1.3 Beams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1.4 Circular CylindricalShells . . . . . . . . . . . . . . . . . . . . . 31
1.5 Spherical Shells . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
1.5.1 Approximationofthe StrainandStress Tensors andAp-
plication of the Virtual Works Theorem . . . . . . . . . 39
1.5.2 Regularity Conditions at the Apexes . . . . . . . . . . . 46
1.6 Variational Form of the Equations Governing Harmonic Vibra-
tions of Plates and Shells . . . . . . . . . . . . . . . . . . . . . 49
1.6.1 VariationalForm of the Plate Equation . . . . . . . . . 50
1.6.2 VariationalForm of the Shells Equations. . . . . . . . . 51
1.7 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
2 Vibratory Response of Thin Structures in vacuo: Resonance
Modes, Forced Harmonic Regime, Transient Regime 53
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
2.2 Vibrations of Constant Cross-Section Beams. . . . . . . . . . . 55
2.2.1 Independent SolutionsfortheHomogenousBeamEquation 55