Varios

IN

MATERIALS SELECTION
IN

SECOND EDITION

MECHANICAL DESIGN
F. ASH BY Cambridge University, England of Engineering,

SECOND EDITION
MICHAEL Department

MICHAEL F. ASHBY

Department of Engineering, Cambridge University, England

OXFORD AUCKLAND BOSTON JOHANNESBURG MELBOURNE NEWDELHI OXFORD AUCKLAND BOSTON JOHANNESBURG MELBOURNE NEW DELHI

Butterworth-Heinemann Linacre House,Jordan Hill, Oxford OX2 8DP 225 Wildwood Avenue, Woburn, MA 0 1801-204 1 A division of Reed Educational and Professional Publishing Ltd

-&A member of the Reed Elsevier plc group
First published by Pergamon Press Ltd 1992 Reprinted with corrections 1993 Reprinted 1995, 1996, 1997 Second edition 1999 Reprinted 2000 (twice)

0 Michael F. Ashby 1999
All rights reserved. No part of thispublication 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 CopyrightLicensing Agency Ltd. 90 Tottenham Court Road, London, England W 1 P OLP. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the publishers

British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library

Library of Congress Cataloguing in Publication Data
A cataloguerecord for this book is available from the Library of Congress ISBN 0 7506 4357 9

Typeset by Laser Words, Madras, India Printed in Great Britain

Acknowledgements
Many colleagues have been generous in discussion, criticism and constructive suggestions. I particularly wish to thank Dr David Cebon, Mr Ken Wallace, Dr Amal Esawi and Dr Ulrike Wegst of the Engineering Design Centre, EngineeringDepartment, Cambridge, Dr Paul Weaver of the Department of Aeronautical Engineering at the University of Bristol and Professor Michael Brown of the Cavendish Laboratory, Cambridge, UK.

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 inEpictetus’ 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 beenstructured; the structure gives rapid access to data and it gives the user great freedom in exploring the potential of choice. The method is available as software* which allows even 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. Thefirst six chapters require little prior knowledge: a first-year engineering knowledge 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 andoptimization, 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 to 10 lecture unit can be based on Chapters 1 to 6; a full 20+ lecture course, with associated project work with the associated software, uses the entire book. Beyond this, the book is intended as a...