James Monroe Gere 1925-2008 James Monroe Gere,Professor Emeritus of Civil Engineering at Stanford University,died in Portola Valley,CA,on January 30,2008.Jim Gere was born on June 14,1925,in Syracuse, NY.He joined the U.S.Army Air Corps at age 17 in 1942,serving in England,France and Germany.After the war,he earned undergraduate and master's degrees in Civil Engineering from the Rensselaer Polytechnic Institute in 1949 and 1951,respectively.He worked as an instructor and later as a Research Associate for Rensselaer between 1949 and 1952.He was awarded one of the first NSF Fellowships,and chose to study at Stanford.He received his Ph.D.in 1954 and was offered a faculty position in Civil Engineering,beginning a 34-year career of engaging his students in challenging topics in mechanics,and structural and earth- quake engineering.He served as Department Chair and Associate Dean of Engineering and in 1974 co-founded the John A.Blume Earthquake Engineering Center at Stanford.In 1980,Jim Gere also became the founding head of the Stanford Committee on Earthquake Preparedness, which urged campus members to brace and strengthen office equipment,furniture,and other contents items that could pose a life safety hazard in the event of an earthquake.That same year,he was invited as one of the first foreigners to study the earthquake-devastated city of Tangshan,China.Jim retired from Stanford in 1988 but con- tinued to be a most valuable member of the Stanford community as he gave freely of his time to advise students and to guide them on various field trips to the California earthquake country. Jim Gere was known for his outgoing manner,his cheerful personality and wonderful smile,his athleticism,and his skill as an educator in Civil Engineering.He authored nine text- books on various engineering subjects starting in 1972 with Mechanics of Materials,a text that was inspired by his teacher and mentor Stephan P.Timoshenko.His other well-known text- books,used in engineering courses around the world,include:Theory of Elastic Stability, co-authored with S.Timoshenko;Matrix Analysis of Framed Structures and Matrix Algebra for Engineers,both co-authored with W.Weaver;Moment Distribution;Earthquake Tables: Structural and Construction Design Manual,co-authored with H.Krawinkler;and Terra Non Firma:Understanding and Preparing for Earthquakes,co-authored with H.Shah. Respected and admired by students,faculty,and staff at Stanford University,Professor Gere always felt that the opportunity to work with and be of service to young people both inside and outside the classroom was one of his great joys.He hiked frequently and regu- larly visited Yosemite and the Grand Canyon national parks.He made over 20 ascents of Half Dome in Yosemite as well as"John Muir hikes"of up to 50 miles in a day.In 1986 he Jim Gere in the Timoshenko hiked to the base camp of Mount Everest,saving the life of a companion on the trip.James Library at Stanford holding a was an active runner and completed the Boston Marathon at age 48,in a time of 3:13. copy of the 2nd edition of this James Gere will be long remembered by all who knew him as a considerate and loving text (photo courtesy of Richard man whose upbeat good humor made aspects of daily life or work easier to bear.His last proj- Weingardt Consultants,Inc.) ect (in progress and now being continued by his daughter Susan of Palo Alto)was a book based on the written memoirs of his great-grandfather,a Colonel (122d NY)in the Civil War. ix
James Monroe Gere 1925–2008 James Monroe Gere, Professor Emeritus of Civil Engineering at Stanford University, died in Portola Valley, CA, on January 30, 2008. Jim Gere was born on June 14, 1925, in Syracuse, NY. He joined the U.S. Army Air Corps at age 17 in 1942, serving in England, France and Germany. After the war, he earned undergraduate and master’s degrees in Civil Engineering from the Rensselaer Polytechnic Institute in 1949 and 1951, respectively. He worked as an instructor and later as a Research Associate for Rensselaer between 1949 and 1952. He was awarded one of the first NSF Fellowships, and chose to study at Stanford. He received his Ph.D. in 1954 and was offered a faculty position in Civil Engineering, beginning a 34-year career of engaging his students in challenging topics in mechanics, and structural and earthquake engineering. He served as Department Chair and Associate Dean of Engineering and in 1974 co-founded the John A. Blume Earthquake Engineering Center at Stanford. In 1980, Jim Gere also became the founding head of the Stanford Committee on Earthquake Preparedness, which urged campus members to brace and strengthen office equipment, furniture, and other contents items that could pose a life safety hazard in the event of an earthquake. That same year, he was invited as one of the first foreigners to study the earthquake-devastated city of Tangshan, China. Jim retired from Stanford in 1988 but continued to be a most valuable member of the Stanford community as he gave freely of his time to advise students and to guide them on various field trips to the California earthquake country. Jim Gere was known for his outgoing manner, his cheerful personality and wonderful smile, his athleticism, and his skill as an educator in Civil Engineering. He authored nine textbooks on various engineering subjects starting in 1972 with Mechanics of Materials, a text that was inspired by his teacher and mentor Stephan P. Timoshenko. His other well-known textbooks, used in engineering courses around the world, include: Theory of Elastic Stability, co-authored with S. Timoshenko; Matrix Analysis of Framed Structures and Matrix Algebra for Engineers, both co-authored with W. Weaver; Moment Distribution; Earthquake Tables: Structural and Construction Design Manual, co-authored with H. Krawinkler; and Terra Non Firma: Understanding and Preparing for Earthquakes, co-authored with H. Shah. Respected and admired by students, faculty, and staff at Stanford University, Professor Gere always felt that the opportunity to work with and be of service to young people both inside and outside the classroom was one of his great joys. He hiked frequently and regularly visited Yosemite and the Grand Canyon national parks. He made over 20 ascents of Half Dome in Yosemite as well as “John Muir hikes” of up to 50 miles in a day. In 1986 he hiked to the base camp of Mount Everest, saving the life of a companion on the trip. James was an active runner and completed the Boston Marathon at age 48, in a time of 3:13. James Gere will be long remembered by all who knew him as a considerate and loving man whose upbeat good humor made aspects of daily life or work easier to bear. His last project (in progress and now being continued by his daughter Susan of Palo Alto) was a book based on the written memoirs of his great-grandfather, a Colonel (122d NY) in the Civil War. ix Jim Gere in the Timoshenko Library at Stanford holding a copy of the 2nd edition of this text (photo courtesy of Richard Weingardt Consultants, Inc.)
Photo Credits Chapter 1.2:Photo by Bryan Tokarczyk,PE/KPFF Tower Engineers 15:Courtesy of MTS Systems Corporation 16:Courtesy of MTS Systems Corporation 18: Courtesy of MTS Systems Corporation 32:Barry Goodno 60:Barry Goodno 66:Vince Streano/Getty Images 67:Barry Goodno 67:Barry Goodno 67: Barry Goodno 68:Barry Goodno 72:Barry Goodno 76:Courtesy of Ameri- can Superconductor 83:Barry Goodno 86:Courtesy Tilt-Up Concrete Association. Chapter 2.88:Joe Raedle/Getty Images 93:Barsik/Dreamstime.com 118:Barros Barros/Getty Images 163:Courtesy of MTS systems corporation 188:Barry Goodno Chapter 3.220:Harald Sund/Getty Images 232:Louie Psihoyos/Getty Images 233: Peter Ginter/Getty Images 290:Barry Goodno 290:Bontrager Race XXX Lite Flat Handlebar,used Courtesy of Bontrager Chapter 4.304:Jupiter Images,2007 307:Joe Gough/Shuttterstock 309:Courtesy of the National Information Service for Earthquake Engineering EERC,University of California,Berkeley.339:Thomasz Gulla/Shuttterstock Chapter 5.350:Lester Lefkowitz/Getty Images 374:Courtesy of AISC 413:Lester Lefkowitz/Getty Images 427:Gabriel M.Covian/Getty Images Chapter 6.454:Chris Harvey/Shutterstock 479:Franz Pfluegl/Shutterstock 527: Barry Goodno 527:Barry Goodno Chapter 7.536:Alfred Pasieka/Peter Arnold,Inc.548:Courtesy Eann Patterson 548: Frans Lemmens/Getty Images 594:Courtesy Omega Engineering Inc. Chapter 8.618:Courtesy of Christian Michel,www.modernairships.info 621: Harald Hoilan Tjostheim/Getty Images 627:Wayne Eastep/Getty Images Chapter 9.676:Courtesy of the National Information Service for Earthquake Engi- neering EERC,University of California,Berkeley.698:Courtesy of the National Information Service for Earthquake Engineering EERC,University of California, Berkeley.700:Tom Brakefield/Getty Images 709:Courtesy of the National Informa- tion Service for Earthquake Engineering EERC,University of California,Berkeley. 720:Malcolm Fife/Getty Images Chapter 10.770:david sanger photography/Alamy 776:Lopatinsky Vladislav/ Shutterstock 812:Courtesy of the National Information Service for Earthquake Engi- neering EERC,University of California,Berkeley. Chapter 11.816:LUSHPIX/UNLISTED IMAGES,INC.833:Lester Lefkowitz/Getty Images 834:Digital Vision/Getty Images 887:Barry Goodno Chapter 12.900:Bob Scott/Getty Images 903:Photo courtesy of Louis Geschwinder. 906:Don Farrall/Getty Images Preface.Richard Weingardt Consultants Inc. X
x Photo Credits Chapter 1. 2: Photo by Bryan Tokarczyk, PE/KPFF Tower Engineers 15: Courtesy of MTS Systems Corporation 16: Courtesy of MTS Systems Corporation 18: Courtesy of MTS Systems Corporation 32: © Barry Goodno 60: © Barry Goodno 66: Vince Streano/Getty Images 67: © Barry Goodno 67: © Barry Goodno 67: © Barry Goodno 68: © Barry Goodno 72: © Barry Goodno 76: Courtesy of American Superconductor 83: © Barry Goodno 86: Courtesy Tilt-Up Concrete Association. Chapter 2. 88: Joe Raedle/Getty Images 93: © Barsik/Dreamstime.com 118: Barros & Barros/Getty Images 163: Courtesy of MTS systems corporation 188: © Barry Goodno Chapter 3. 220: Harald Sund/Getty Images 232: Louie Psihoyos/Getty Images 233: Peter Ginter/Getty Images 290: © Barry Goodno 290: Bontrager Race XXX Lite Flat Handlebar, used Courtesy of Bontrager Chapter 4. 304: © Jupiter Images, 2007 307: Joe Gough/Shuttterstock 309: Courtesy of the National Information Service for Earthquake Engineering EERC, University of California, Berkeley. 339: Thomasz Gulla/Shuttterstock Chapter 5. 350: Lester Lefkowitz/Getty Images 374: Courtesy of AISC 413: Lester Lefkowitz/Getty Images 427: Gabriel M. Covian/Getty Images Chapter 6. 454: Chris Harvey/Shutterstock 479: Franz Pfluegl/Shutterstock 527: © Barry Goodno 527: © Barry Goodno Chapter 7. 536: Alfred Pasieka/Peter Arnold, Inc. 548: Courtesy Eann Patterson 548: Frans Lemmens/Getty Images 594: Courtesy Omega Engineering Inc. Chapter 8. 618: Courtesy of Christian Michel, www.modernairships.info 621: Harald Høilan Tjøstheim/Getty Images 627: Wayne Eastep/Getty Images Chapter 9. 676: Courtesy of the National Information Service for Earthquake Engineering EERC, University of California, Berkeley. 698: Courtesy of the National Information Service for Earthquake Engineering EERC, University of California, Berkeley. 700: Tom Brakefield/Getty Images 709: Courtesy of the National Information Service for Earthquake Engineering EERC, University of California, Berkeley. 720: Malcolm Fife/Getty Images Chapter 10. 770: © david sanger photography/Alamy 776: Lopatinsky Vladislav/ Shutterstock 812: Courtesy of the National Information Service for Earthquake Engineering EERC, University of California, Berkeley. Chapter 11. 816: LUSHPIX/UNLISTED IMAGES, INC. 833: Lester Lefkowitz/Getty Images 834: Digital Vision/Getty Images 887: © Barry Goodno Chapter 12. 900: Bob Scott/Getty Images 903: Photo courtesy of Louis Geschwinder. 906: Don Farrall/Getty Images Preface. Richard Weingardt Consultants Inc
Preface Mechanics of Materials is a basic engineering subject that must be under- stood by anyone concerned with the strength and physical performance of structures,whether those structures are man-made or natural.The subject matter includes such fundamental concepts as stresses and strains,defor- mations and displacements,elasticity and inelasticity,strain energy,and load-carrying capacity.These concepts underlie the design and analysis of a huge variety of mechanical and structural systems. At the college level,mechanics of materials is usually taught during the sophomore and junior years.The subject is required for most stu- dents majoring in mechanical,structural,civil,biomedical,aeronautical, and aerospace engineering.Furthermore,many students from such diverse fields as materials science,industrial engineering,architecture, and agricultural engineering also find it useful to study this subject. About this Book The main topics covered in this book are the analysis and design of structural members subjected to tension,compression,torsion,and bending,including the fundamental concepts mentioned in the first para- graph.Other topics of general interest are the transformations of stress and strain,combined loadings,stress concentrations,deflections of beams,and stability of columns. Specialized topics include the following:Thermal effects,dynamic loading,nonprismatic members,beams of two materials,shear centers, pressure vessels,and statically indeterminate beams.For completeness and occasional reference,elementary topics such as shear forces,bending moments,centroids,and moments of inertia also are presented.As an aid to the student reader,each chapter begins with a Chapter Overview and closes with a Chapter Summary Review in which the key points pre- sented in the chapter are listed for quick review (in preparation for examinations on the material).Each chapter also opens with a photo- graph of a component or structure which illustrates the key concepts to be discussed in that chapter. Much more material than can be taught in a single course is included in this book,and therefore instructors have the opportunity to select the topics they wish to cover.As a guide,some of the more specialized topics are identified in the table of contents by stars. 灯
xi Preface Mechanics of Materials is a basic engineering subject that must be understood by anyone concerned with the strength and physical performance of structures, whether those structures are man-made or natural. The subject matter includes such fundamental concepts as stresses and strains, deformations and displacements, elasticity and inelasticity, strain energy, and load-carrying capacity. These concepts underlie the design and analysis of a huge variety of mechanical and structural systems. At the college level, mechanics of materials is usually taught during the sophomore and junior years. The subject is required for most students majoring in mechanical, structural, civil, biomedical, aeronautical, and aerospace engineering. Furthermore, many students from such diverse fields as materials science, industrial engineering, architecture, and agricultural engineering also find it useful to study this subject. About this Book The main topics covered in this book are the analysis and design of structural members subjected to tension, compression, torsion, and bending, including the fundamental concepts mentioned in the first paragraph. Other topics of general interest are the transformations of stress and strain, combined loadings, stress concentrations, deflections of beams, and stability of columns. Specialized topics include the following: Thermal effects, dynamic loading, nonprismatic members, beams of two materials, shear centers, pressure vessels, and statically indeterminate beams. For completeness and occasional reference, elementary topics such as shear forces, bending moments, centroids, and moments of inertia also are presented. As an aid to the student reader, each chapter begins with a Chapter Overview and closes with a Chapter Summary & Review in which the key points presented in the chapter are listed for quick review (in preparation for examinations on the material). Each chapter also opens with a photograph of a component or structure which illustrates the key concepts to be discussed in that chapter. Much more material than can be taught in a single course is included in this book, and therefore instructors have the opportunity to select the topics they wish to cover. As a guide, some of the more specialized topics are identified in the table of contents by stars
xii PREFACE Considerable effort has been spent in checking and proofreading the text so as to eliminate errors,but if you happen to find one,no matter how trivial,please notify me by e-mail (bgoodno@ce.gatech.edu).Then we can correct any errors in the next printing of the book. Examples Examples are presented throughout the book to illustrate the theoretical concepts and show how those concepts may be used in practical situations. In some cases,photographs have been added showing actual engineering structures or components to reinforce the tie between theory and applica- tion.The examples vary in length from one to four pages,depending upon the complexity of the material to be illustrated.When the emphasis is on concepts,the examples are worked out in symbolic terms so as to better illustrate the ideas,and when the emphasis is on problem-solving,the examples are numerical in character.In selected examples throughout the text,graphical display of results (e.g.,stresses in beams)has been added to enhance the student's understanding of the problem results. Problems In all mechanics courses,solving problems is an important part of the learning process.This textbook offers more than 1,000 problems for homework assignments and classroom discussions.Approximately 40% of the problems are new or significantly revised in the seventh edition. The problems are placed at the end of each chapter so that they are easy to find and don't break up the presentation of the main subject matter. Also,an unusually difficult or lengthy problem is indicated by attaching one or more stars (depending upon the degree of difficulty)to the prob- lem number,thus alerting students to the time necessary for solution. In general,problems are arranged in order of increasing difficulty. Answers to all problems are listed near the back of the book. Units Both the International System of Units (SI)and the U.S.Customary System (USCS)are used in the examples and problems.Discussions of both systems and a table of conversion factors are given in Appendix A. For problems involving numerical solutions,odd-numbered problems are in USCS units and even-numbered problems are in SI units.This conven- tion makes it easy to know in advance which system of units is being used in any particular problem.In addition,tables containing properties of structural-steel shapes in both USCS and SI units have been added to Appendix E so that solution of beam analysis and design examples and end-of-chapter problems can be carried out in either USCS or SI units. References and Historical Notes References and historical notes appear immediately after the last chapter in the book.They consist of original sources for the subject matter plus brief biographical information about the pioneering scientists,engineers
xii PREFACE Considerable effort has been spent in checking and proofreading the text so as to eliminate errors, but if you happen to find one, no matter how trivial, please notify me by e-mail (bgoodno@ce.gatech.edu). Then we can correct any errors in the next printing of the book. Examples Examples are presented throughout the book to illustrate the theoretical concepts and show how those concepts may be used in practical situations. In some cases, photographs have been added showing actual engineering structures or components to reinforce the tie between theory and application. The examples vary in length from one to four pages, depending upon the complexity of the material to be illustrated. When the emphasis is on concepts, the examples are worked out in symbolic terms so as to better illustrate the ideas, and when the emphasis is on problem-solving, the examples are numerical in character. In selected examples throughout the text, graphical display of results (e.g., stresses in beams) has been added to enhance the student’s understanding of the problem results. Problems In all mechanics courses, solving problems is an important part of the learning process. This textbook offers more than 1,000 problems for homework assignments and classroom discussions. Approximately 40% of the problems are new or significantly revised in the seventh edition. The problems are placed at the end of each chapter so that they are easy to find and don’t break up the presentation of the main subject matter. Also, an unusually difficult or lengthy problem is indicated by attaching one or more stars (depending upon the degree of difficulty) to the problem number, thus alerting students to the time necessary for solution. In general, problems are arranged in order of increasing difficulty. Answers to all problems are listed near the back of the book. Units Both the International System of Units (SI) and the U.S. Customary System (USCS) are used in the examples and problems. Discussions of both systems and a table of conversion factors are given in Appendix A. For problems involving numerical solutions, odd-numbered problems are in USCS units and even-numbered problems are in SI units. This convention makes it easy to know in advance which system of units is being used in any particular problem. In addition, tables containing properties of structural-steel shapes in both USCS and SI units have been added to Appendix E so that solution of beam analysis and design examples and end-of-chapter problems can be carried out in either USCS or SI units. References and Historical Notes References and historical notes appear immediately after the last chapter in the book. They consist of original sources for the subject matter plus brief biographical information about the pioneering scientists, engineers
PREFACE xiii and mathematicians who created the subject of mechanics of materials.A separate name index makes it easy to look up any of these historical figures. Appendixes Reference material appears in the appendixes at the back of the book.Much of the material is in the form of tables-properties of plane areas,properties of structural-steel shapes,properties of structural lumber,deflections and slopes of beams,and properties of materials (Appendixes D through H, respectively). In contrast,Appendixes A and B are descriptive-the former gives a detailed description of the SI and USCS systems of units,and the latter presents the methodology for solving problems in mechanics.Included in the latter are topics such as dimensional consistency and significant digits.Lastly,as a handy time-saver,Appendix C provides a listing of commonly used mathematical formulas. S.P.Timoshenko(1878-1972)and J.M.Gere (1925-2008) Many readers of this book will recognize the name of Stephen P. Timoshenko-probably the most famous name in the field of applied mechanics.Timoshenko is generally recognized as the world's most out- standing pioneer in applied mechanics.He contributed many new ideas and concepts and became famous for both his scholarship and his teach- ing.Through his numerous textbooks he made a profound change in the teaching of mechanics not only in this country but wherever mechanics is taught.Timoshenko was both teacher and mentor to James Gere and provided the motivation for the first edition of this text,authored by James M.Gere and published in 1972;the second and each subsequent edition of this book were written by James Gere over the course of his long and distinguished tenure as author,educator,and researcher at Stanford University.James Gere started as a doctoral student at Stanford in 1952 and retired from Stanford as a professor in 1988 having authored this and eight other well known and respected text books on mechanics, and structural and earthquake engineering.He remained active at Stanford as Professor Emeritus until his death in January of 2008. A brief biography of Timoshenko appears in the first reference at the back of the book,and also in an August 2007 STRUCTURE maga- zine article entitled "Stephen P.Timoshenko:Father of Engineering Mechanics in the U.S."by Richard G.Weingardt,P.E.This article pro- vides an excellent historical perspective on this and the many other engineering mechanics textbooks written by each of these authors. Acknowledgments To acknowledge everyone who contributed to this book in some manner is clearly impossible,but I owe a major debt to my former Stanford teachers, especially my mentor and friend,and lead author,James M.Gere.I am also indebted to the many teachers of mechanics and reviewers of the book who have helped to shape this textbook in its various editions over
PREFACE xiii and mathematicians who created the subject of mechanics of materials. A separate name index makes it easy to look up any of these historical figures. Appendixes Reference material appears in the appendixes at the back of the book. Much of the material is in the form of tables—properties of plane areas, properties of structural-steel shapes, properties of structural lumber, deflections and slopes of beams, and properties of materials (Appendixes D through H, respectively). In contrast, Appendixes A and B are descriptive—the former gives a detailed description of the SI and USCS systems of units, and the latter presents the methodology for solving problems in mechanics. Included in the latter are topics such as dimensional consistency and significant digits. Lastly, as a handy time–saver, Appendix C provides a listing of commonly used mathematical formulas. S.P. Timoshenko (1878–1972) and J.M. Gere (1925–2008) Many readers of this book will recognize the name of Stephen P. Timoshenko—probably the most famous name in the field of applied mechanics. Timoshenko is generally recognized as the world’s most outstanding pioneer in applied mechanics. He contributed many new ideas and concepts and became famous for both his scholarship and his teaching. Through his numerous textbooks he made a profound change in the teaching of mechanics not only in this country but wherever mechanics is taught. Timoshenko was both teacher and mentor to James Gere and provided the motivation for the first edition of this text, authored by James M. Gere and published in 1972; the second and each subsequent edition of this book were written by James Gere over the course of his long and distinguished tenure as author, educator, and researcher at Stanford University. James Gere started as a doctoral student at Stanford in 1952 and retired from Stanford as a professor in 1988 having authored this and eight other well known and respected text books on mechanics, and structural and earthquake engineering. He remained active at Stanford as Professor Emeritus until his death in January of 2008. A brief biography of Timoshenko appears in the first reference at the back of the book, and also in an August 2007 STRUCTURE magazine article entitled “Stephen P. Timoshenko: Father of Engineering Mechanics in the U.S.” by Richard G. Weingardt, P.E. This article provides an excellent historical perspective on this and the many other engineering mechanics textbooks written by each of these authors. Acknowledgments To acknowledge everyone who contributed to this book in some manner is clearly impossible, but I owe a major debt to my former Stanford teachers, especially my mentor and friend, and lead author, James M. Gere. I am also indebted to the many teachers of mechanics and reviewers of the book who have helped to shape this textbook in its various editions over