Composite Materials in Aerospace Design Soviet Advanced Composites Technology Series Serieseditors:I.N.Fridlyander, Russian Academy of Sciences,Moscow, Russia I.H.Marshall, UniversityofPaisley, Paisley, UK This series forms a unique record of research, developmentand applica tion ofcomposite materials and components in the former Soviet Union. Thematerialpresentedineachvolume,muchofitpreviouslyunpublished and classified until recently, gives the reader a detailed insight into the theoryandmethodologyemployedandthe resultsachievedby the Soviet Union's top scientists and engineers in relation to this versatile class of materials. Titles in the series 1. CompositeManufacturingTechnology Editors: A.G.Bratukhinand V.5.Bogolyubov 2. Ceramic-and Carbon-matrixComposites Editor:V.I.Trefilov 3. Metal MatrixComposites Editor:I.N.Fridlyander 4. PolymerMatrix Composites Editor: R.E.Shalin 5. Fibre Science and Technology Editor:V.I.Kostikov 6. CompositeMaterials in Aerospace Design Editors:G.I.Zagainovand G.E.Lozino-Lozinski Composite Materials in Aerospace Design Edited by G.I. Zagainov DirectoroftheCentralAero-hydrodynamicInstitute Zhukovski MoscowRegiotl Russia and G.B. Lozino-Lozinsky NPOMolniya Moscow Russia imi SPRINGER-SCIENCE+BUSINESS MEDIA, B.V. ;('jSpringerScience+BusinessMedia Dordrecht Softcoverreprintofthehardcover1stedition1996 Originallypublished byChapman& Hali TypesetinPalatino10/12ptbyThomsonPress(1)Ltd.,NewDelhi ISBN978-94-010-4254-3 IISBN 978-94-011-0575-0 (eeBook) DOI10.1007/978-94-011-0575-0 Apartfrom any fairdealingfor thepurposesofresearchorprivatestudy, orcriticismorreview,aspermittedundertheUKCopyright Designs and PatentsAct,1988,thispublication maynotbereproduced,stored,or transmitted,inanyformorbyany means,withoutthepriorpermission in writingofthe publishers,orinthecaseofreprographicreproductiononly inaccordancewiththetermsofthe licencesissuedby theCopyright LicensingAgencyintheUK,orinaccordancewiththe termsofIicences issuedbytheappropriateReproductionRightsOrganizationoutsidethe UK.Enquiriesconceming reproductionoutside thetermsstatedhere shouldbesenttothepublishersat the Londonaddressprintedon this page. Thepublishermakesnorepresentation,expressorimplied,withregard totheaccuracy ofthe informationcontained inthisbook and cannot acceptanylegal responsibilityorliabilityforanyerrorsoromissions that maybemade. Acataloguerecordfor thisbookisavailablefrom the British Library r>, ~: Printedonacid-freetextpaper,manufactured inaccordancewith ANSI/NISOZ39.48-1992(PermanenceofPaper). Composite Materials in Aerospace Design Soviet Advanced Composites Technology Series Series editors: J.N. Fridlyander, Russian Academy of Sciences, Moscow, Russia LH. Marshall, University of Paisley, Paisley, UK This series forms a unique record of research, development and applica tion of composite materials and components in the former Soviet Union. The material presented in each volume, much of it previously unpublished and classified until recently, gives the reader a detailed insight into the theory and methodology employed and the results achieved by the Soviet Union's top scientists and engineers in relation to this versatile class of materials. Titles in the series 1. Composite Manufacturing Technology Editors: A.C. Bratukhin and V.S. Bogolyubov 2. Ceramic-and Carbon-matrix Composites Editor: V.L Trefilov 3. Metal Matrix Composites Editor: J.N. Fridlyander 4. Polymer Matrix Composites Editor: R.E. Shalin 5. Fibre Science and Technology Editor: V.L Kostikov 6. Composite Materials in Aerospace Design Editors: C.L Zagainov and C.E. Lozino-Lozinski Composite Mat erials in Aerospace Design Edited by G.L Zagainov Director of the Central Aero-hydrodynamic Institute Zhukovski Moscow Region Russia and G.E. Lozino-Lozinsky NPOMolniya Moscow Russia CHAPMAN & HALL London· Glasgow· Weinheim . New York· Tokyo· Melbourne· Madras Published by Chapman & Hall, 2-6 Boundary Row, London SE18HN, UK Chapman & Hall, 2-6 Boundary Row, London SE18HN, UK Blackie Academic & Professional, Wester Cleddens Road, Bishopbriggs, Glasgow G64 2NZ, UK Chapman & Hall GmbH, Pappelallee 3,69469 Weinheim, Germany Chapman & Hall USA, 115 Fifth Avenue, New York, NY 10003, USA Chapman & Hall Japan, ITP-Japan, Kyowa Building, 3F,2-2-1 Hirakawacho, Chiyoda-ku, Tokyo 102, Japan Chapman & Hall Australia, 102 Dodds Street, South Melbourne, Victoria 3205, Australia Chapman & Hall India, R. Seshadri, 32 Second Main Road, CIT East, Madras 600035, India First edition 1996 © 1996 Chapman & Hall Typeset in Palatino 10/12 pt by Thomson Press (I) Ltd., New Delhi ISBN 0 412 58470 0 Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the UK Copyright Designs and Patents Act, 1988, this publication may not be reproduced, stored, or transmitted, in any form or by any means, without the prior permission in writing of the publishers, or in the case of reprographic reproduction only in accordance with the terms of the licences issued by the Copyright Licensing Agency in the UK, or in accordance with the terms of licences issued by the appropriate Reproduction Rights Organization outside the UK. Enquiries concerning reproduction outside the terms stated here should be sent to the publishers at the London address printed on this page. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that maybe made. A catalogue record for this book is available from the British Library §i Printed on acid-free text paper, manufactured in accordance with ANSI/NISO Z39.48-1992 (Permanence of Paper). Contents List of contributors ix Series preface xi Preface xiii 1 Specific features of composite-material structural design 1 V.F. Kutyinov and AA Ionov 1.1 Introduction 1 1.2 Strength requirements of the airworthiness standards 8 1.3 Design of composite constructions and elements 18 1.4 Experimental studies of composite structures 81 1.5 Validation of strength computations 113 References 116 2 Analysis of stiffness, strength and fatigue characteristics of multilayer composites 118 G.P. Sukhobokova and Yu.P. Trunin 2.1 Introduction 118 2.2 Analysis of laminate stiffness 119 2.3 Analysis of laminated-composite strength 126 2.4 Fatigue and cyclic crack resistance of composites 140 References 155 3 Methods of composite structural strength analysis 156 V.M. Andrienko, K.M. Ierusalimsky, AA Ionov, AL. Rubina, G.P. Sukhobokova, AA Dudchenko and AN. Yelpatyevsky 3.1 Stability analysis of composite laminates 156 3.2 Strength analysis of composite rods 169 3.3 Analysis of sandwich cylindrical panels 183 3.4 Analysis of wafer panels 189 3.5 Analysis of stiffened stringer panels 196 3.6 Stability analysis of thin conic and cylindrical shells 225 3.7 Stability analysis of sandwich conic and cylindrical shells 242 3.8 Analysis of panels with cut-outs 260 vi Contents 3.9 Analysis of beam structures 273 References 291 4 Methods for experimental and analytical evaluation of the residual strength of composite structures with stress concentration 295 Yu.P. Trunin, A.E. Ushakov and S.A. Lurie 4.1 Experimental procedures for investigating the stress concentration effect on strength of composites 295 4.2 Model of static fracture toughness and fracture criteria 304 4.3 Residual strength of damaged structural elements 315 4.4 Methods for increasing the residual strength of damaged structural elements 323 4.5 Fracture of a flat specimen with delamination under compression 329 References 341 5 Methods of design and analysis of joints 343 A.A. Ionov, V.F. Kutyinovand Yu.P. Trunin 5.1 Analysis of mechanical joints 343 5.2 Analysis of adhesive joints 351 References 370 6 Application of the finite-element method to the structural analysis of composite structures 372 A.S. Dzuba, A.A. Ionov and V.F. Kutyinov 6.1 Introduction 372 6.2 Method of analysis of complex load-carrying structures made of composite materials 372 6.3 Mathematical models of typical fragments of structures made of composite materials 376 6.4 Results of analysis of stress-strain state and strength of composite structures using the example of cargo compartment doors 379 References 387 7 Characteristics of the certification of composite structures 389 Yu.A. Stuchalkin, A. V. Stewart and A.E. Ushakov 7.1 Introduction 389 7.2 Enlarged scatter of strength properties and additional safety factor 389 7.3 Evaluation of reliability and safety factors in the case of short-term strength reduction with subsequent restoration 401 7.4 Damage tolerance evaluation 405