PREFACE TO THE FOURTH EDITION The addition of several new topics and the updating of numerous segments in both sections of the book enables the fourth edition of this text to continue to serve both as a textbook and as a reference volume. These changes reflect recent developments in our understanding of deformation and fracture processes in structural materials More than 130 additional references have been added to the text, raising the total to more than 1200. Twenty new example problems and 50 additional figures have been distributed throughout the manuscript to enable the reader to more readily understand the subject matter. Approximately 40 additional homework problems have been added at the end of most chapters; the solutions manual has been updated and is available to qualified users A new section on the isostress analysis, which characterizes the strength and stiffness of composites, has been added to complement the isostrain analysis that was introduced in the third edition. To establish the groundwork for expanded coverage of the fracture studies of ceramics, a new section on the modulus of rupture has been added. For students who possess a limited exposure to strength of materials concepts, the stress analysis of thin-walled cylinders has been included near the end of Chap ter 1. This discussion will help the reader in later chapters when dealing with fracture problems associated with thin-walled pressure vessels; these include circumstance surrounding leak-before-break criteria. In connection with crystallographic texture a new section on plastic anisotropy has been added to Chapter 3. A new section on creep fracture micromechanisms has been added at the conclusion of Chapter 5 Two new analytical sections have been added to Chapter 7 that deal with the Weibull analysis of the statistical nature of fracture and the generation of thermal stresses and thermal shock-induced fracture. Several new example problems have been added to the important discussions of fracture mechanics in Chapter 8. The discussions dealing with the fracture toughness of metals, ceramics, and polymers have been updated and compared with respect to the controlling crack tip shielding mechanisms. Recent observations regarding environmental threshold test procedures re included in Cl Discussion of‘ safe-life,"“fail-safe,"’and“ retirement-for- cause’ fatigue life design procedures have been added to Chapters 12 and 13. Also, a new section on procedures for the avoidance of fatigue damage, including the development of favor able residual compressive stresses and pretensioning of load-bearing members, com- pletes the discussion of Chapter 12. New topics added to Chapter 13 include:( 1) calculation and prediction of FCP data based on fundamental crystal properties;( 2) load interaction-induced macroscopic fracture surface appearance; an discussion dealing with the fatigue crack propagation response of polymers and