Contents 1 OVERVIEW 1 1.1 Definition of Structure 1 1.2 Building Structure 1 1.3 Structural Planning and Design 3 1.4 Types of Loads 6 1.5 Types of Stress 7 1.6 Structural Forms in Nature 7 1.7 Structural Elements in Buildings 10 1.8 Structure and Architectural Character 17 1.9 Cost 18 1.10 Building Codes 19 1.11 Accuracy of Computations 19 2 STATICS 21 2.1 Introduction 21 2.2 Forces 21 2.3 Components and Resultants 22 2.4 Equilibrium of Concurrent Forces 32 2.5 Moments and Couples 42 2.6 Ideal Support Conditions 49 2.7 Rigid-Body Concept and Free-Body Diagrams 53 2.8 Equilibrium of Cantilevered Members 54 2.9 Equilibrium of Simple Beams and Frames 60 2.10 Two-Force Members 68 2.11 Graphical Techniques 79 2.12 Shed and Gable Members 82 2.13 Stability and Determinacy 87 2.14 Pinned Frames 90 2.15 Simple Cable Statics 96 2.16 Maxwell Diagram Analysis of Suspension Structures 112 2.17 Maxwell Diagram Analysis of Other Structures 129 2.18 Conclusion and Procedure 144 3 STRUCTURAL PROPERTIES OF AREAS 147 3.1 Introduction 147 3.2 Centroids 147 3.3 Moment of Inertia 158 3.4 Parallel Axis Theorem 167 3.5 Radius of Gyration 174 4 STRESS AND STRAIN 179 4.1 Types of Stress 179 4.2 Basic Connection Stresses 181 4.3 Strain 181 4.4 Stress Versus Strain 187 4.5 Stiffness 188 4.6 Total Axial Deformation 191 4.7 Thermal Stresses and Strains 193 4.8 Allowable Stress Design and Limit States Design 198 5 PROPERTIES OF STRUCTURAL MATERIALS 201 5.1 Introduction 201 5.2 Nature of Wood 201 5.3 Concrete and Reinforced Concrete 205 5.4 Structural Steel 206 5.5 Masonry and Reinforced Masonry 207 5.6 Creep 208 6 SHEAR AND MOMENT 209 6.1 Definitions and Sign Conventions 209 6.2 Shear and Moment Equations 211 6.3 Significance of Zero Shear 222 6.4 Load, Shear, and Moment Relationships 225 6.5 Uniformly Varying Loads 233 7 FLEXURAL STRESSES 239 7.1 Introduction 239 7.2 Flexural Strain 240 7.3 Flexural Stress 241 7.4 Section Modulus 258 7.5 Lateral Buckling and Stability 266 8 SHEARING STRESSES 269 8.1 Nature of Shearing Stresses 269 8.2 Diagonal Tension and Compression 270 8.3 Basic Horizontal Shearing Stress Equation 271 8.4 Horizontal Shearing Stresses in Timber Beams 280 8.5 Horizontal Shearing Stresses in Steel Beams 283 9 DEFLECTION AND INDETERMINATE BEAMS 289 9.1 Introduction 289 9.2 Moment-Area Method 290 9.3 Principle of Superposition 300 9.4 Use of Deflection Formulas 302 9.5 Superposition and Indeterminate Structures 305 9.6 Theorem of Three Moments 311 9.7 Loading Patterns 320 10 BEAM DESIGN AND FRAMING 323 10.1 Introduction 323 10.2 Shape of Beam Cross Sections 324 10.3 "Ideal" Beams 324 10.4 Properties of Materials 326 10.5 Tributary Area 327 10.6 Framing Direction 329 10.7 Selecting Wood Beams 332 10.8 Selecting Steel Beams 351 10.9 Design Aids for Wood and Steel 369 11 ELASTIC BUCKLING OF COLUMNS 371 11.1 Columns as Building Structural Elements 371 11.2 Column Failure Modes 372 11.3 The Euler Theory 373 11.4 Influence of Different End Conditions 379 11.5 Intermediate Lateral Bracing 390 11.6 Limits to the Applicability of the Euler Equation 399 11.7 Eccentric Loading and Beam-Columns 400 12 TRUSSES 401 12.1 Introduction 401 12.2 Analysis by Joint Equilibrium 404 12.3 Analysis by Maxwell Diagram 415 12.4 Method of Sections 422 12.5 Special Types of Trusses 430 APPENDICES 433 APPENDIX A Derivation of Basic Flexural Stress Equation 433 APPENDIX B Derivation of Basic Horizontal Shearing Stress Equation 437 APPENDIX C Derivation of Euler Column Buckling Equation 440 APPENDIX D Weights of Selected Building Materials 442 APPENDIX E Properties of Selected Materials 443 APPENDIX F Properties of Areas 445 APPENDIX G Proof of Moment-Area Theorems 447 APPENDIX H Allowable Stresses and Modulus of Elasticity Values for Selected Structural Sawn Lumber 451 APPENDIX I Wood Section Properties 453 APPENDIX J Properties of Selected Steel Sections 455 APPENDIX K Shear, Moment, and Deflection Equations 459 APPENDIX L Introduction to the SI Metric System 462 ANSWERS TO PROBLEMS 467 INDEX 495