PREFACE TO THE SECOND EDITION The many developments and clarifications in the theory of elasticity and its applications which have occurred since the first edition was written are reflected in numerous additions and emendations in the present edition.The arrangement of the book remains the same for the most part. The treatments of the photoelastic method,two-dimensional problems in curvilinear coordinates,and thermal stress have been rewritten and enlarged into separate new chapters which present many methods and solutions not given in the former edition.An appendix THEORY OF ELASTICITY on the method of finite differences and its applications,including the relaxation method,has been added.New articles and paragraphs Copyright,1934,by the United Engineering Trustees,Ine.Copyright,1951,by the MeGraw- incorporated in the other chapters deal with the theory of the strain Hill Book Company,Ine.Printed in the United gauge rosette,gravity stresses,Saint-Venant's prineiple,the components States of America.All rights reserved.This book, of rotation,the reciprocal theorem,general solutions,the approximate or parts thereof,may not be reproduced in any character of the plane stress solutions,center of twist and center of form without permission of the publishers. shear,torsional stress concentration at fillets,the approximate treat- XIIL ment of slender (e.g.,solid airfoil)sections in torsion and bending, and the cireular cylinder with a band of pressure. 6M719 Problems for the student have been added covering the text as far as the end of the chapter on torsion. It is a pleasure to make grateful acknowledment of the many helpful suggestions which have been contributed by readers of the book. S.TIMOSHENKO J.N.GooDIER PALO ALTO,CALIF February,1951 THE MAPLE PRESS COMPANY,TORK,PA