Fatigue of Materials and Structures E-Book

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

Seitenzahl: 498

Veröffentlichungsjahr: 2013

Beschreibung

The design of mechanical structures with predictable and improved durability cannot be achieved without a thorough understanding of the mechanisms of fatigue damage and more specifically the relationships between the microstructure of materials and their fatigue properties. Written by leading researchers in the field, this book, along with the complementary books Fatigue of Materials and Structures: Fundamentals and Application to Damage and Design (both also edited by Claude Bathias and André Pineau), provides an authoritative, comprehensive and unified treatment of the mechanics and micromechanisms of fatigue in metals, polymers and composites. Each chapter is devoted to one of the major classes of materials or to different types of fatigue damage, thereby providing overall coverage of the field. This book deals with multiaxial fatigue, thermomechanical fatigue, fretting-fatigue, influence of defects on fatigue life, cumulative damage and damage tolerance, and will be an important and much used reference for students, practicing engineers and researchers studying fracture and fatigue in numerous areas of materials science and engineering, mechanical, nuclear and aerospace engineering.

Leseprobe

Table of Contents

Foreword

Chapter 1. Multiaxial Fatigue

1.1. Introduction

1.2. Experimental aspects

1.3. Criteria specific to the unlimited endurance domain

1.4. Low cycle fatigue criteria

1.5. Calculating methods of the lifetime under multiaxial conditions

1.6. Conclusion

1.7. Bibliography

Chapter 2. Cumulative Damage

2.1. Introduction

2.2. Nonlinear fatigue cumulative damage

2.3. A nonlinear cumulative fatigue damage model

2.4. Damage law of incremental type

2.5. Cumulative damage under fatigue-creep conditions

2.6. Conclusion

2.7. Bibliography

Chapter 3. Damage Tolerance Design

3.1. Background

3.2. Evolution of the design concept of “fatigue” phenomenon

3.3. Impact of damage tolerance on design

3.4. Calculation of a “stress intensity factor”

3.5. Performing some “damage tolerance” calculations

3.6. Application to the residual strength of thin sheets

3.7. Propagation of cracks subjected to random loading in the aeronautic industry

3.8. Conclusion

3.9. Damage tolerance within the gigacyclic domain

3.10. Bibliography

Chapter 4. Defect Influence on the Fatigue Behavior of Metallic Materials

4.1. Introduction

4.2. Some facts

4.3. Approaches

4.4. A few examples

4.5. Prospects

4.6. Conclusion

4.7. Bibliography

Chapter 5. Fretting Fatigue: Modeling and Applications

5.1. Introduction

5.2. Experimental methods

5.3. Fretting fatigue analysis

5.4. Applications under fretting conditions

5.5. Palliatives to combat fretting fatigue

5.6. Conclusions

5.7. Bibliography

Chapter 6. Contact Fatigue

6.1. Introduction

6.2. Classification of the main types of contact damage

6.3. A few results on contact mechanics

6.4. Elastic limit

6.5. Elastoplastic contact

6.6. Application to modeling of a few contact fatigue issues

6.7. Conclusion

6.8. Bibliography

Chapter 7. Thermal Fatigue

7.1. Introduction

7.2. Characterization tests

7.3. Constitutive and damage models at variable temperatures

7.4. Applications

7.5. Conclusion

7.6. Bibliography

List of Authors

Index

First published 2011 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc. Adapted and updated from Fatigue des matériaux et des structures 4 published 2009 in France by Hermes Science/Lavoisier © LAVOISIER 2009

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

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

www.iste.co.uk

www.wiley.com

© ISTE Ltd 2011

The rights of Claude Bathias and André Pineau to be identified as the authors of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Cataloging-in-Publication Data

Fatigue des matériaux et des structures. English

Fatigue of materials and structures : application to design and damage / edited by Claude Bathias, Andre Pineau.

p. cm.

Includes bibliographical references and index.

ISBN 978-1-84821-291-6

1. Materials--Fatigue. I. Bathias, Claude. II. Pineau, A. (André) III. Title.

TA418.38.F3713 2010

620.1’126--dc22

2010040728

British Library Cataloguing-in-Publication Data

A CIP record for this book is available from the British Library

ISBN 978-1-84821-291-6

Foreword

This book on fatigue, combined with two other recent publications edited by Claude Bathias and André Pineau1, are the latest in a tradition that traces its origins back to a summer school held at Sherbrooke University in Quebec in the summer of 1978 which was organized by Professors Claude Bathias (then at the University of Technology of Compiegne, France) and Jean Pierre Bailon of Ecole Polytechnique, Montreal, Quebec. This meeting was held under the auspices of a program of cultural and scientific exchanges between France and Quebec. As one of the participants in this meeting, I was struck by the fact that virtually all of the presentations provided a tutorial background and an in-depth review of the fundamental and practical aspects of the field as well as a discussion of recent developments. The success of this summer school led to the decision that it would be of value to make these lectures available in the form of a book which was published in 1980. This broad treatment made the book appealing to a wide audience. Indeed, within a few years, dog-eared copies of “Sherbrooke” could be found on the desks of practicing engineers, students and researchers in France and in French-speaking countries. The original book was followed by an equally successful updated version that was published in 1997 which preserved the broad appeal of the first book. This book represents a part of the continuation of the approach taken in the first two editions while providing an even more in-depth treatment of this crucial but complex subject.

It is also important to draw attention to the highly respected “French School” of fatigue which has been at the forefront in integrating the solid mechanics and materials science aspects of fatigue. This integration led to the development of a deeper fundamental understanding thereby facilitating application of this knowledge to real engineering problems from microelectronics to nuclear reactors. Most of the authors who have contributed to the current edition have worked together over the years on numerous high-profile, critical problems in the nuclear, aerospace, and power generating industries. The informal teaming over the years perfectly reflects the mechanics/materials approach and, in terms of this book, provides a remarkable degree of continuity and coherence to the overall treatment.

The approach and ambiance of the “French School” is very much in evidence in a series of bi-annual international colloquia. These colloquia are organized by a very active “fatigue commission” within the French Society of Metals and Materials (SF2M) and are held in Paris in the spring. Indeed, these meetings have contributed to an environment which fostered the publication of this series.

The first two editions (in French), while extremely well-received and influential in the French-speaking world, were never translated into English. The third edition was recently published (again in French) and has been very well received in France. Many English-speaking engineers and researchers with connections to France strongly encouraged the publication of this third edition in English. The current three books on fatigue were translated from the original four volumes in French2 in response to that strong encouragement and wide acceptance in France.

In his preface to the second edition, Prof. Francois essentially posed the question (liberally translated), “Why publish a second volume if the first does the job?” A very good question indeed! My answer would be that technological advances place increasingly severe performance demands on fatigue-limited structures. Consider, as an example, the economic, safety and environmental requirements in the aerospace industry. Improved economic performance derives from increased payloads, greater range and reduced maintenance costs. Improved safety, demanded by the public, requires improved durability and reliability. Reduced environmental impact requires efficient use of materials and reduced emission of pollutants. These requirements translate into higher operating temperatures (to increase efficiency), increased stresses (to allow for lighter structures and greater range), improved materials (to allow for higher loads and temperatures) and improved life prediction methodologies (to set safe inspection intervals). A common thread running through these demands is the necessity to develop a better understanding of fundamental fatigue damage mechanisms and more accurate life prediction methodologies (including, for example, application of advanced statistical concepts). The task of meeting these requirements will never be completed; advances in technology will require continuous improvements in materials and more accurate life prediction schemes. This notion is well illustrated in the rapidly developing field of gigacycle fatigue. The necessity to design against fatigue failure in the regime of 109 + cycles in many applications required in-depth research which in turn has called into question the old, comfortable notion of a fatigue limit at 107 cycles. New developments and approaches are an important component of this edition and are woven through all of the chapters of the three books.

It is not the purpose of this preface to review all of the chapters in detail. However, some comments about the organization and over-all approach are in order. The first chapter in the first book3 provides a broad background and historical context and sets the stage for the chapters in the subsequent books. In broad outline, the experimental, physical, analytical and engineering fundamentals of fatigue are developed in this first book. However, the development is done in the context of materials used in engineering applications and numerous practical examples are provided which illustrate the emergence of new fields (e.g. gigacycle fatigue) and evolving methodologies (e.g. sophisticated statistical approaches). In the second4 and third5 books, the tools that are developed in the first book are applied to newer classes of materials such as composites and polymers and to fatigue in practical, challenging engineering applications such as high temperature fatigue, cumulative damage and contact fatigue.

These three books cover the most important fundamental and practical aspects of fatigue in a clear and logical manner and provide a sound basis that should make them as attractive to English-speaking students, practicing engineers, and researchers as they have proved to be to our French colleagues.

Stephen D. ANTOLOVICH

Professor of Materials and Mechanical EngineeringWashington State University

and

Professor Emeritus

Georgia Institute of Technology

December 2010

1. C. BATHIAS, A. PINEAU (eds.), Fatigue of Materials and Structures: Fundamentals, ISTE, London and John Wiley & Sons, New York, 2010.C. BATHIAS, A. PINEAU (eds.), Fatigue of Materials and Structures: Application to Damage, ISTE, London and John Wiley & Sons, New York, 2011.

2. C. BATHIAS, A. PINEAU (eds.), Fatigue des matériaux et des structures, Volumes 1, 2, 3 and 4, Hermes, Paris, 2009.

3. C. BATHIAS, A. PINEAU (eds.), Fatigue of Materials and Structures: Fundamentals, ISTE, London and John Wiley & Sons, New York, 2010.

4. C. BATHIAS, A. PINEAU (eds.), Fatigue of Materials and Structures: Application to Damage, ISTE, London and John Wiley & Sons, New York, 2011.

5. This book.

Chapter 1

Multiaxial Fatigue1

1.1. Introduction

Nowadays, everybody agrees on the fact that good multiaxial constitutive equations are needed in order to study the stress-strain response of materials. After many studies, a number of models have been developed, and the quality/cost ratio of the different existing approaches is well defined in the literature. Things are very different in the case of the characterization of multiaxial fatigue. In this domain, as in others related to the study of damage and failure phenomena, the phase of settling which leads to the classification of the different approaches has not been carried out yet, which can explain why so many different models are available. These models are not only different because of the different types of equations they present, but also because of their critical criteria. The main reason is that fatigue phenomena involve some local mechanisms, which are thus controlled by some local physical variables, and which are thus much more sensitive to the microstructure of the material rather than to the behavior laws which only give a global response. It is then difficult to present in a single chapter the entire variety of the existing fatigue criteria for the endurance as well as for the low cycle fatigue domains.

Nevertheless, right at the design phase, the improvements of the methods and the tools of numerical simulation, along with the growth supported by any available calculation power, can provide some historical data stress and strain to the engineer in charge of the study. The multiaxiality of both stresses and strains is a fundamental aspect for a high number of safety components: rolling issues, contactfriction problems, anisothermal multiaxial fatigue issues, etc. Multiaxial fatigue can be observed within many structures which are used in every day life (suspension hooks, subway gates, automotive suspensions). In addition to these observations, researchers and engineers regularly pay much attention to some important and common applications: fatigue of railroads involving some complex phenomena, where the macroscopic analysis is not always sufficient due to metallurgical modifications within the contact layer. Friction can also be a critical phenomenon at any scale, from the industrial component to micromachines. The thermo-mechanical aspects are also fundamental within the hot parts of automotive engines, of nuclear power stations, of aeronautical engines, but also in any section of the hydrogen industry for instance. The effects of fatigue then have to be evaluated using adapted models, which consider some specific mechanisms. This chapter presents a general overview of the situation, stressing the necessity of defending some rough models which can be clearly applied to some random loadings rather than a simple smoothing effect related to a given experiment, which does not lead to any interesting general use.

Brown and Miller, in a classification released in 1979 [BRO 79], distinguish four different phases in the fatigue phenomenon: (i) nucleation or microinitiation of the crack; (ii) growth of the crack depending on a maximum shearing plane; (iii) propagation normal to the traction strain; (iv) failure of the specimen. The germination and growth steps usually occur within a grain located at the surface of the material. The growth of the crack begins with a step, which is called short crack, during which the geometry of the crack is not clearly defined. Its propagation direction is initially related to the geometry and to the crystalline orientations of the grains, and is sometimes called micropropagation. The microscopic initiation, from the engineers point of view, will also be the one which will get most attention from the mechanical engineer because of its volume element: it perfectly matches the moment where the size of the crack becomes large enough for it to impose its own stress field, which is then much more important than the microstructural aspects. At this scale (usually several times the size of the grains), it is possible to give a geometric sense to the crack, and to specifically treat the problem within the domain of failure mechanics, whereas the first ones are mainly due to the fatigue phenomenon itself. This chapter gathers the models which can be used by the engineer and which lead to the definition of microscopic initiation.