FOURTH EDITION DEFORMATION AND FRACTURE MECHANICS OF ENGINEERING MATERIALS 27了 RICHARD W. HERTZBERG New Jersey Zinc Professo of Materials Science and Engineering and Director, Mechanical Behavior Laboratory Materials Research Center JOHN WILEY SoNS INC
A47 The Liberty Bell/ Bettmann Archive Acquisitions Editor Cliff Robichaud Assistant Editor Catherine Beckham O mETU Production edito bra riege Ken Santor Manufacturing Coordinator Dor lllustration Coordinator Anna Methord 0050355857 This book was set in 10.5/12.5 Times Roman by Ruttle, Shaw Wetherill and printed and bound by Hamilton Printing. The cover was printed by Phoenix Color. Recognizing the importance of preserving what has been written, it is a policy of John Wiley Sons, Inc. to have books of enduring value published in the United States printed on acid-free paper, and we exert our best efforts to that ook was manufactured by a mill whose forest management programs include sustained yield harvesting of its timberlands. Sustained yield harvesting principles ensure that the number of trees cut each year does not exceed the amount of new growth Copyright o 1996 by John wiley Sons, Inc. All rights reserved. Published simultaneously in Canada. No part of this publication may be reproduced, in a retrieval system or transmitted or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States opyright Act, without either the prior written permission of the Publisher, or puyment of the appropriate per- copy fee to the( (978)750-4470. Requests to the Publisher for permission should be addressed to the missions Department, John Wiley Sons, Inc, Ill River Street, Hoboken, NJ07030, (201)748-6011,fax(201)748-6008.E-mail:PermReq@WileY.com. To order books or for customer service please, call 1(800)-CALL-WILEY (225-594 Hertzberg. Richard w.1937- Deformation and fracture mechanics of engineering materials Richard W. Hertzberg 76H461995 9535234
ABOUT THE COVER The Liberty Bell appears on the cover of this textbook because the crack is intema tionally known and recognized more than any other fracture. However, there is con- siderable confusion as to the history of the Bell and how it gained such worldwide recognition. The following is intended to highlight major events in the Bell's existence from the casting foundry to the present. o commemorate the fiftieth anniversary of the granting of william Penns Charter of Liberties, the Pennsylvania Assembly purchased a bell for the Statehouse. Since there were no qualified bell foundries in the region, the bell was cast at the Whitechapel Foundry in London, England. The inscription on the bell was to read"Proclaim liberty through all the land unto all the inhabitants thereof, ""(Leviticus 25: 10). On its ompletion, the bell was shipped to Philadelphia and placed in the Statehouse belfr To the dismay of all, the bell cracked the first time it was struck. John Pass and Charles Stow, two area residents, agreed to recast the bell in time for the Charter of Liberty's jubilee celebration. After adjusting the alloy chemistry and recasting the bell twice, these amateur bell founders produced a bell with an acceptable tone. For their services, Pass and Stow were paid $295.25 and given a free advertisement: note their names on the shoulder of the bell Not leaving anything to chance, the Pennsylvania Assembly commissioned a sec ond bell from the Whitechapel Foundry, which arrived from England when Pass and Stow had completed the third casting of the original bell. What were they to do with two bells? It was ultimately decided that the original bell (also known as the Liberty Bell) be used for grand occasions such as convening townsfolk for the first public reading of the Declaration of Independence and the second Whitechapel bell be used as the town's clockbell During the Revolutionary War, the Liberty Bell was taken to Allentown, Pennsyl vania, to safeguard it from the advancing British armies. The city fathers were less concemed with protecting an American historical treasure(the bell had no historical value at that time)than with preventing the British from melting such bells to produce new artillery pieces. Cannon metal (also known as Admiralty bronze) contains 88% copper and 12%0 tin whereas bell metal contains roughly twice as much tin. After the bell was returned to Philadelphia in 1778, it continued to ring until 1835 when it cracked while tolling the funeral of Chief Justice Marshall. (The second whitechay bell was given to a church in 1828, before being destroyed in a fire. After grinding the mating surfaces of the crack to prevent them from rubbing together, the Liberty Bell was struck once again in 1846 to celebrate Washington,s birthday. After ringing
Vi ABOUT THE COVER for several hours, the original crack extended into the shoulder region. Since that time, the bell has effectively remained silent. After being sent on a series of national tours, beginning with a trip to New or 1885, the Liberty Bell has become a symbol independence. It is on permanent exhibition in the historical section of Philadelphia
To my wife Linda and my children michelle, Jason, and Nicholas