Fatigue Limit in Metals E-Book

Claude Bathias

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 112

Veröffentlichungsjahr: 2013

Beschreibung

Is there a fatigue limit in metals? This question is the main focus of this book.
Written by a leading researcher in the field, Claude Bathias presents a thorough and authoritative examination of the coupling between plasticity, crack initiation and heat dissipation for lifetimes that exceed the billion cycle, leading us to question the concept of the fatigue limit, both theoretically and technologically.
This is a follow-up to the Fatigue of Materials and Structures series of books previously published in 2011.

Contents

1. Introduction on Very High Cycle Fatigue.
2. Plasticity and Initiation in Gigacycle Fatigue.
3. Heating Dissipation in the Gigacycle Regime.

About the Authors

Claude Bathias is Emeritus Professor at the University of Paris 10-La Defense in France. He started his career as a research engineer in the aerospace and military industry where he remained for 20 years before becoming director of the CNRS laboratory ERA 914 at the University of Compiègne in France. He has launched two international conferences about fatigue: International Conference on the Fatigue of Composite Materials (ICFC) and Very High Cycle Fatigue (VHCF).

This new, up-to-date text supplements the book Fatigue of Materials and Structures, which had been previously published by ISTE and John Wiley in 2011. A thorough review of coupling between plasticity, crack priming, and thermal dissipation for lifespans higher than a billion of cycle has led us to question the concept of fatigue limit, from both the theoretical and technological point of view. This book will address that and more.

Leseprobe

Contents

Acknowledgements

1 Introduction On Very High Cycle Fatigue

1.1. Fatigue limit, endurance limit and fatigue strength

1.2. Absence of an asymptote on the SN curve

1.3. Initiation and propagation

1.4. Fatigue limit or fatigue strength

1.5. SN curves up to 109 cycles

1.6. Deterministic prediction of the gigacycle fatigue strength

1.7. Gigacycle fatigue of alloys without flaws

1.8. Initiation mechanisms at 109 cycles

1.9. Conclusion

1.10. Bibliography

2 Plasticity and Initiation in Gigacycle Fatigue

2.1. Evolution of the initiation site from LCF to GCF

2.2. Fish-eye growth

2.3. Stresses and crack tip intensity factors around spherical and cylindrical voids and inclusions

2.4. Estimation of the fish-eye formation from the Paris–Hertzberg law

2.5. Example of fish-eye formation in a bearing steel

2.6. Fish-eye formation at the microscopic level

2.7. Instability of microstructure in very high cycle fatigue (VHCF)

2.8. Industrial practical case: damage tolerance at 109 cycles

2.9. Bibliography

3 Heating Dissipation in the Gigacycle Regime

3.1. Temperature increase at 20 kHz

3.2. Detection of fish-eye formation

3.3. Experimental verification of Nf by thermal dissipation

3.4. Relation between thermal energy and cyclic plastic energy

3.5. Effect of metallurgical instability at the yield point in ultrasonic fatigue

3.6. Gigacycle fatigue of pure metals

3.7. Conclusion

3.8. Bibliography

Index

First published 2014 in Great Britain and the United States 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 Ltd27-37 St George’s RoadLondon SW19 4EUUK

www.iste.co.uk

John Wiley & Sons, Inc.111 River StreetHoboken, NJ 07030USA

www.wiley.com

© ISTE Ltd 2014

The rights of Claude Bathias 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 Control Number: 2013950132

British Library Cataloguing-in-Publication Data A CIP record for this book is available from the British Library ISSN: 2051-2481 (Print) ISSN: 2051-249X (Online) ISBN: 978-1-84821-476-7

Acknowledgments

The author is grateful to Professor Paul. C. Paris for his constant encouragement, for his participation in several cooperative research projects on gigacycle fatigue and for his writing of several papers included in this book.

I wish to acknowledge the assistance of colleagues and friends: S. Antolovich (Georgia Tech), H. Mughrabi (Erlangen University), T. Palin-Luc (Ecole Nationale des Arts et Métiers (ENSAM)) and P. Herve (University Paris ouest).

I wish to express special thanks to some PhD students of the University of Paris, who were involved in gigacycle fatigue research during the 2000s: I. Marines and R. Perez Mora (from Mexico), H. Xue, Z. Huang, Weiwei Du and Chong Wang (from China), and A. Nikitin (from Russia).

This work was supported by several financial sources. The most important among them are Ascometal, Safran, Renault, A2MI, Sandvik, Vallourec, Hansen and the French Agency for Research (L’Agence Nationale de la Recherche – ANR).

1

Introduction on Very High Cycle Fatigue

This chapter is a summary of several decades of reasearch on gigacycle fatigue of metals. For more detail please see references [BAT 04] and [BAT 10].

1.1. Fatigue limit, endurance limit and fatigue strength

Fatigue limit, endurance limit and fatigue strength are all expressions used to describe a property of materials under cyclic loading: the amplitude (or range) of that can be applied to the material without causing . In these cases, a number of cycles (usually 10) are chosen to represent the fatigue life of the material.