Third edition Materials Selection in Mechanical Design Michael F. ashby
Materials selection in Mechanical Design Third edition Michael f. Ashby ELSEVIER BUTTERWORTH AMSTERDAM BOSTON● HEIDELBERG· LONDON· NEW YORK· OXFORD PARs。SAND|EGo· SAN FRANC|ScO·S| NGAPORE. SYDNEY· TOKYO
Materials Selection in Mechanical Design Third Edition Michael F. Ashby AMSTERDAM BOSTON HEIDELBERG LONDON NEW YORK OXFORD PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO
Butterworth-Heineman Linacre House, Jordan Hill, Oxford OX2 8DP 0 Corporate Drive, Burlington, MA 01803 First published by Pergamon Press 1992 Second edition 1999 Copyright o 1992, 1999, 2005 Michael F. Ashby. All rights reserved The right of Michael F. Ashby to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988 otocopying or storing in amay be reproduced in any material form(including No part of this publication or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the ns of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England WIT 4LP. Applications for the copyright holder's written ermission to reproduce any part of this publication should be addressed Permissions may be sought directly from Elsevier's Science and Technology Rights Department in Oxford, UK: phone: (+44)(0)1865843830, fax:(+44)1865 853333 e-mail: permissions @elsevier. co. uk. You may also complete your request on-line via theElsevierhomepage(http://www.elsevier.com),byselecting"customerSupport and then Obtaining Permissions British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data A catalog record for this book is available from the Library of Congress ISBN0750661682 For information on all elsevier butterworthheinemann publicationsvisitourwebsiteathttp://books.elsevier by Newgen Imaging Systems(P)Ltd, Chennai, Ind Printed and bound in Italy Working together to grow libraries in developing countries www.clsevicr.comiwww.bookaid.orgIwww.sabre.org elsevier BOOK AID Sabre Foundation
Butterworth-Heinemann Linacre House, Jordan Hill, Oxford OX2 8DP 30 Corporate Drive, Burlington, MA 01803 First published by Pergamon Press 1992 Second edition 1999 Third edition 2005 Copyright # 1992, 1999, 2005 Michael F. Ashby. All rights reserved The right of Michael F. Ashby to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988 No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England W1T 4LP. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the publisher Permissions may be sought directly from Elsevier’s Science and Technology Rights Department in Oxford, UK: phone: (þ44) (0) 1865 843830, fax: (þ44) 1865 853333, e-mail: permissions@elsevier.co.uk. You may also complete your request on-line via the Elsevier homepage (http://www.elsevier.com), by selecting ‘Customer Support’ and then ‘Obtaining Permissions’ British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data A catalog record for this book is available from the Library of Congress ISBN 0 7506 6168 2 For information on all Elsevier Butterworth-Heinemann publications visit our website at http://books.elsevier.com Typeset by Newgen Imaging Systems (P) Ltd, Chennai, India Printed and bound in Italy Working together to grow libraries in developing countries www.elsevier.com | www.bookaid.org | www.sabre.org
Preface Materials, of themselves, affect us little; it is the way we use them which influences our lives. Epictetus, AD 50-100, Discourses Book 2, Chapter 5 New materials advanced engineering design in Epictetus'time. Today, with more materials than ever before, the opportunities for innovation are immense. But advance is possible only if a pro- cedure exists for making a rational choice. This book develops a systematic procedure for selecting materials and processes, leading to the subset which best matches the requirements of a design. It is unique in the way the information it contains has been structured. The structure gives rapid access to data and allows the user great freedom in exploring the potential of choice. The method is available as software, giving greater flexibility. The approach emphasizes design with materials rather than materials"science", although the underlying science is used, whenever possible, to help with the structuring of criteria for selection. The first eight chapters require little prior knowledge: a first-year grasp of materials and mechanics is enough. The chapters dealing with shape and multi-objective selection are a little more advanced but can be omitted on a first reading. As far as possible the book integrates materials selection with other aspects of design; the relationship with the stages of design and optimization and with the mechanics of materials, are developed throughout. At the teaching level, the book is intended as the text for 3rd and 4th year engineering courses on Materials for Design: a 6-10 lecture unit can be based on Chapters 1-6; a full 20+ lecture course, with associated project work with the associated software uses the entire book s Beyond this, the book is intended as a reference text of lasting value. The method, the charts and les of performance indices have application in real problems of materials and process selection; and the catalogue of"useful solutions"is particularly helpful in modelling-an essential ingre- dient of optimal design. The reader can use the book(and the software)at increasing levels of sophistication as his or her experience grows, starting with the material indices developed in the case studies of the text, and graduating to the modelling of new design problems, leading to new material indices and penalty functions, and new-and perhaps novel-choices of material. This continuing education aspect is helped by a list of Further reading at the end of most chapters, and by a set of exercises in Appendix E covering all aspects of the text. Useful reference material is assembled in appendices at the end of the book Like any other book, the contents of this one are protected by copyright. Generally, it is an infringement to copy and distribute materials from a copyrighted source. But the best way to use he charts that are a central feature of the book is to have a clean copy on which you can draw try out alternative selection criteria, write comments, and so forth; and presenting the conclusion of a selection exercise is often most easily done in the same way. Although the book itself is copyrighted, the reader is authorized to make unlimited copies of the charts, and to reproduce these, with proper reference to their source, as he or she wishes M.F. Ashby Cambridge, July 2004 The CES materials and process selection platform, available from Granta Design Ltd, Rustat House, 62 Clifton Road, Cambridge CBI 7eg,Uk(wwW.grantadesign.com)
Preface Materials, of themselves, affect us little; it is the way we use them which influences our lives. Epictetus, AD 50–100, Discourses Book 2, Chapter 5. New materials advanced engineering design in Epictetus’ time. Today, with more materials than ever before, the opportunities for innovation are immense. But advance is possible only if a procedure exists for making a rational choice. This book develops a systematic procedure for selecting materials and processes, leading to the subset which best matches the requirements of a design. It is unique in the way the information it contains has been structured. The structure gives rapid access to data and allows the user great freedom in exploring the potential of choice. The method is available as software,1 giving greater flexibility. The approach emphasizes design with materials rather than materials ‘‘science’’, although the underlying science is used, whenever possible, to help with the structuring of criteria for selection. The first eight chapters require little prior knowledge: a first-year grasp of materials and mechanics is enough. The chapters dealing with shape and multi-objective selection are a little more advanced but can be omitted on a first reading. As far as possible the book integrates materials selection with other aspects of design; the relationship with the stages of design and optimization and with the mechanics of materials, are developed throughout. At the teaching level, the book is intended as the text for 3rd and 4th year engineering courses on Materials for Design: a 6–10 lecture unit can be based on Chapters 1–6; a full 20þ lecture course, with associated project work with the associated software, uses the entire book. Beyond this, the book is intended as a reference text of lasting value. The method, the charts and tables of performance indices have application in real problems of materials and process selection; and the catalogue of ‘‘useful solutions’’ is particularly helpful in modelling — an essential ingredient of optimal design. The reader can use the book (and the software) at increasing levels of sophistication as his or her experience grows, starting with the material indices developed in the case studies of the text, and graduating to the modelling of new design problems, leading to new material indices and penalty functions, and new — and perhaps novel — choices of material. This continuing education aspect is helped by a list of Further reading at the end of most chapters, and by a set of exercises in Appendix E covering all aspects of the text. Useful reference material is assembled in appendices at the end of the book. Like any other book, the contents of this one are protected by copyright. Generally, it is an infringement to copy and distribute materials from a copyrighted source. But the best way to use the charts that are a central feature of the book is to have a clean copy on which you can draw, try out alternative selection criteria, write comments, and so forth; and presenting the conclusion of a selection exercise is often most easily done in the same way. Although the book itself is copyrighted, the reader is authorized to make unlimited copies of the charts, and to reproduce these, with proper reference to their source, as he or she wishes. M.F. Ashby Cambridge, July 2004 1 The CES materials and process selection platform, available from Granta Design Ltd, Rustat House, 62 Clifton Road, Cambridge CB1 7EG, UK (www.grantadesign.com)
Acknowledgements Many colleagues have been generous in discussion, criticism, and constructive suggestions I particularly wish to thank Professor Yves Brechet of the University of Grenoble; Professor Anthony Evans of the University of California at Santa Barbara; Professor John Hutchinson of Harvard University; Dr David Cebon; Professor Norman Fleck; Professor Ken Wallace; Dr. John Clarkson; Dr Hugh Shercliff of the Engineering Department, Cambridge University; Dr Amal Esawi of the American University in Cairo, Egypt; Dr Ulrike Wegst of the Max Planck Institute for Materials Research in Stuttgart, Germany; Dr Paul Weaver of the Department of Aeronautical Engineering at the University of Bristol; Professor Michael Brown of the Cavendish Laboratory, Cambridge, UK, and the staff of Granta Design Ltd, Cambridge, UK
Acknowledgements Many colleagues have been generous in discussion, criticism, and constructive suggestions. I particularly wish to thank Professor Yves Bre´chet of the University of Grenoble; Professor Anthony Evans of the University of California at Santa Barbara; Professor John Hutchinson of Harvard University; Dr David Cebon; Professor Norman Fleck; Professor Ken Wallace; Dr. John Clarkson; Dr. Hugh Shercliff of the Engineering Department, Cambridge University; Dr Amal Esawi of the American University in Cairo, Egypt; Dr Ulrike Wegst of the Max Planck Institute for Materials Research in Stuttgart, Germany; Dr Paul Weaver of the Department of Aeronautical Engineering at the University of Bristol; Professor Michael Brown of the Cavendish Laboratory, Cambridge, UK, and the staff of Granta Design Ltd, Cambridge, UK