Fatigue design: life expectancy of machine parts

337 Pages·2019·15.702 MB·English

by  Torbilo, Vladimir, Zahavi, Eliahu

FATIGUE
DESIGN
Life Expectancy
of Machine Parts

FATIGUE
DESIGN
Life Expectancy
of Machine Parts
Eliahu Zahavi
with Vladimir Torbilo
CRC Press
Taylor & Francis Group
Boca Raton London New York
CRC Press is an imprint of the
Taylor & Francis Group, an informa business
Library of Congress Cataloging-in-Publication Data
Zahavi, Eliahu.
Life expectancy of machine parts : fatigue design / Eliahu Zahavi, Jesa H. Kreiner.
p. cm.
“A Solomon Press book.”
Includes bibliographical references and index.
ISBN 0-8493-8970-4 (alk. paper)
1. Machine parts. 2. Materials—Fatigue. I. Kreiner, Jesa H. II. Title.
TJ243.Z29 1996
621.8'2—dc20 96-14021
CIP
This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted
with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made
to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity
of all materials or for the consequences of their use.
Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopying, microfilming, and recording, or by any information storage or retrieval system,
without prior permission in writing from the publisher.
CRC Press, Inc.’s consent does not extend to copying for general distribution, for promotion, for creating new works,
or for resale. Specific permission must be obtained in writing from CRC Press for such copying.
Direct all inquiries to CRC Press, Inc., 2000 Corporate Blvd., N.W., Boca Raton, Florida 33431.
© 1996 by CRC Press
No claim to original U.S. Government works
International Standard Book Number 0-8493-8970-4
Library of Congress Card Number 96-14021
Printed in the United States of America 2 3 4 5 6 7 8 9 0
Printed on acid-free paper
CONTENTS
Preface ix
Chapter 1 Introduction 1
References 4
Chapter 2 Solid Mechanics 5
2.1 Elasticity 5
2.1.1 Stress 5
2.1.2 Deformation and strain 11
2.1.3 Stress-strain relation 14
2.1.4 Energy and work 15
2.1.5 Equivalent stresses and strains 18
2.2 Plasticity 21
2.2.1 Yield function 21
2.2.2 Stress-strain relation 24
v
vi Contents
2.2.3 Work hardening 27
2.2.4 Incremental and deformation theories 28
2.3 Finite Element Method 29
2.3.1 The equilibrium condition 29
2.3.2 Nonlinear problems 35
References 39
Chapter 3 Stress Method 41
3.1 Tests and Test Results 42
3.1.1 Standard fatigue tests 42
3.1.2 Statistical analysis of fatigue data 58
3.2 One-Dimensional Analysis of Machine Parts 64
3.2.1 Infinite fatigue life 65
3.2.2 Limited fatigue life 80
3.3 Multiaxial Analysis 88
3.3.1 Combining fluctuating stresses 89
3.3.2 Design of rotating transmission shaft 91
3.4 Cumulative Damage 93
3.4.1 Palmgren-Miner rule 93
3.4.2 Spectrum loading 95
References 99
Chapter 4 Strain Method 101
4.1 One-Dimensional Analysis 101
4.1.1 Monotonic properties (tension test) 102
4.1.2 Cyclic properties 106
4.1.3 Fatigue life 116
4.2 Multiaxial Analysis 129
4.2.1 Multiaxial stress and strain components 129
4.2.2 Equivalent strains and stresses 130
4.2.3 Computing fatigue life 133
References 139
Chapter 5 Crack Propagation 141
5.1 Fracture Mechanics 142
5.1.1 Linear elastic fracture mechanics 142
5.1.2 Griffith theory of fracture 149
5.1.3 Extension of LEFM into the plastic domain 155
Contents vii
Crack Propagation Under Fatigue Load 163
5.2.1 Constant amplitude loading 163
5.2.2 Variable amplitude loading 170
Mixed Loading And Multiaxial Effects 173
5.3.1 Plane cracks under mixed loading 173
5.3.2 Three-dimensional cracks under one-dimensional loading 177
References 180
Chapter 6 Surface Integrity and Fatigue 183
6.1 Surface Roughness 183
6.1.1 Surface roughness form and measurement 184
6.1.2 Effect of processing on surface roughness 185
6.1.3 Change of surface roughness in service 192
6.1.4 Surface roughness and fatigue 193
6.2 Metal Structure and Strain Hardening of the Surface Layer 196
6.2.1 Surface layer formation 196
6.2.2 Strain-hardening parameters 197
6.2.3 Effect of processing on the surface layer (strain hardening) 199
6.2.4 Stability of strain hardening 204
6.2.5 Influence of surface layer on fatigue 205
6.3 Residual Stresses 217
6.3.1 Classification 217
6.3.2 Origin of residual stresses 218
6.3.3 Measurement of residual stresses 219
6.3.4 Effect of processing methods on residual stresses 223
6.3.5 Relaxation of residual stresses 230
6.3.6 Effect of residual stresses on fatigue 232
6.4 Processing Methods and Fatigue: Summary 235
References 238
Chapter 7 Fatigue Life Improvement 239
7.1 Shot Peening 240
7.1.1 Shot peening devices 240
7.1.2 Surface integrity 242
7.2 Rolling 245
7.2.1 Parameters of rolling 246
7.2.2 Surface integrity 246
7.3 Burnishing 252
References 257
viii Contents
Chapter 8 Diagnosis of Fatigue Cases 259
8.1 Fatigue of Fuse Pin in an Aircraft 260
8.1.1 The problem 260
8.1.2 Problem analysis 260
8.1.3 Crack propagation 267
8.1.4 Conclusion 271
8.2 Crack Propagation in a Breech Block 272
8.2.1 The problem 272
8.2.2 FE analysis 272
8.2.3 Conclusion 283
8.3 Thermal Fatigue of a Coke Drum 283
8.3.1 The problem 283
8.3.2 FE analysis 288
8.3.3 Conclusion 294
References 296
Appendix 297
Nomenclature 311
Index 316
PREFACE
I o make the book as applicable as possible, the initiator of this work took an inter­
disciplinary approach, combining in one volume the two related fields concerned with
fatigue design: theoretical foundation of fatigue analysis and study of behavior of mate­
rials in manufacture of machine parts. The solved fatigue failure cases, taken from real
situations, illustrate the inter-dependency of the two. The theoretical foundation and
the cases (chapters 1, 2, 3, 4, 5, and 8) written by Eliahu Zahavi, cover a wide range
of fatigue problems: from simple to nonlinear in multi-axial space. On the other hand,
the thorough coverage of surface phenomena in chapters 6 and 7 puts in proper per­
spective the other perils that must be considered in designing the machine parts for
fatigue life, and is the contribution of Vladimir Torbilo.
Practical constraints prevent us from acknowledging here personally all those who
helped us accomplish what we set out to do, not least our families for their devotion
and forbearance. Among the few we did single out, a sincere appreciation goes to Pro­
fessor A. Berkowits, of Technion, Israel, for the review of the chapters on fatigue
theories and for the kind permission to include his latest maxims here. To each one of
the reviewers of case studies, Emanuel Liban, Simha Bar-Nefi and David Barlam, our
gratitude for their comments and professional advice.