McCormac

738 Pages·2011·34.52 MB·English

FIFTH EDITION
JACK C. McCORMAC
STEPHEN F. CSERNAK
Prentice Hall
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Ubrary or Congress Cataloging-in-Publication Data
McCormac. Jack C.
Structural steel dcsi!!n I Jack C. McCormac. Stephen F. Csemak. - 5th ed.
p.cm.
ISBN-13: 978·0·13-607948-4
ISBN-10: 0-13-607948-2
I. Building. Iron and steel-Textbooks. 2. Steel. Structural-Textbooks. I. Cwmak, Stephen F. II 1itle.
TA684.M25 2011
624.1'821- dc22
2011010788
Prentice Hall
is an imprint of
10 9 8 7 6 5 4 3 2 I
----
PEARSON
ISBN-13: 978-0-13-607948-4
www.pearsonhighered.com ISBN-10: 0-13-607948-2
Preface
This textbook has been prepared with the hope that its readers will, as have so many engi
neers in the past, become interested in structural steel design and want to maintain and
increase their knowledge on the subject throughout their careers in the engineering and
construction industries. The material was prepared primarily for an introductory course
in the junior or senior year but the last several chapters may be used for a graduate class.
The authors have assumed that the student has previously taken introductory courses
in mechanics of materials and structural analysis.
The authors' major objective in preparing this new edition was to update the text
to conform to both the American Institute of Steel Construction (A IS C) 2010
Specification for Structural Steel Buildings and the 14th edition of the AISC Steel
Construction Manual published in 2011.
WHAT'S NEW IN THIS EDITION
Several changes to the text were made to the textbook in this edition:
1. End of chapter Problems for Solution have been added for Chapter 1 of the
textbook.
2. The load factors and load combinations defined in Chapter 2 of the textbook
and used throughout the book in example problems and end of chapter problems
for solution have been revised to meet those given in the ASCE 7-10 and Part 2
of the AISC Steel Construction Manual.
3. The classification of compression sections for local buckling defined in Chapter 5
of the textbook has been revised to the new definition given in Section B4.1 of
the new AISC Specification. For compression, sections are now classified as
non-slender element or slender element sections.
4. The AISC Specification provides several methods to deal with stability analy
sis and the design of beam-columns. In Chapter 7 of the textbook, the Effective
Length Method (ELM) is still used, though a brief introduction to the Direct
Analysis Method ( DM) has been added. A more comprehensive discussion of
the DM is reserved for Chapter 11 of the text.
5. In Chapter 11 of the textbook, both the Direct Analysis Method and the Effective
Length Method are presented for the analysis and design of beam-columns. This
is to address the fact that the presentation of the Direct Analysis Method was
moved from an appendix to Chapter C of the new AISC Specification while the
Effective Length Method moved from Chapter C to Appendix 7.
6. Most of the end of chapter Problems for Solution for Chapters 2 through 11
have been revised. For Chapters 12 through 18 about half the problems have
been revised.
7. Various photos were updated throughout the textbook.
iii
iv Preface
The authors would like to express appreciation to Dr. Bryant G. Nielson of Clemson
University for his assistance in developing the changes to this manuscript and to Sara
Elise Roberts, former Clemson University graduate student, for her assistance in the
review of the end of chapter problems and their solutions. In addition, the American
Institute of Steel Construction was very helpful in providing advance copies of the AISC
Specification and Steel Construction Manual revisions. Finally, we would like to thank
our families for their encouragement and support in the revising of the manuscript of
this textbook.
We also thank the reviewers and users of the previous editions of this book for their
suggestions, corrections, and criticisms. We welcome any comments on this edition.
Jack C. McCormac, P.E.
Stephen F. Csernak, P.E.
Contents
Preface iii
CHAPTER 1 Introduction to Structural Steel Design 1
1.1 Advantages of Steel as a Structural Material 1
1.2 Disadvantages of Steel as a Structural Material 3
1.3 Early Uses of Iron and Steel 4
1.4 Steel Sections 7
1.5 Metric Units 12
1.6 Cold-Formed Light-Gage Steel Shapes 12
1.7 Stress-Strain Relationships in Structural Steel 13
1.8 Modern Structural Steels 19
1.9 Uses of High-Strength Steels 22
1.10 Measurement of Toughness 24
1.11 Jumbo Sections 26
1.12 Lamellar Tearing 26
1.13 Furnishing of Structural Steel 27
1.14 The Work of the Structural Designer 30
1.15 Responsibilities of the Structural Designer 31
1.16 Economical Design of Steel Members 31
1.17 Failure of Structures 34
1.18 Handling and Shipping Structural Steel 37
1.19 Calculation Accuracy 37
1.20 Computers and Structural Steel Design 37
1.21 Problems for Solution 38
CHAPTER 2 Specifications, Loads, and Methods of Design 39
2.1 Specifications and Building Codes 39
2.2 Loads 41
2.3 Dead Loads 41
2.4 Live Loads 42
v
vi Contents
2.5 Environmental Loads 45
2.6 Load and Resistance Factor Design (LRFD)
and Allowable Strength Design (ASD) 51
2.7 Nominal Strengths 52
2.8 Shading 52
2.9 Computation of Loads for LRFD and ASD 52
2.10 Computing Combined Loads with LRFD Expressions 53
2.11 Computing Combined Loads with ASD Expressions 57
2.12 Two Methods of Obtaining an Acceptable Level of Safety 58
2.13 Discussion of Sizes of Load Factors and Safety Factors 59
2.14 Author's Comment 60
2.15 Problems for Solution 60
CHAPTER 3 Analysis of Tension Members 62
3.1 Introduction 62
3.2 Nominal Strengths of Tension Members 65
3.3 Net Areas 67
3.4 Effect of Staggered Holes 69
3.5 Effective Net Areas 74
3.6 Connecting Elements for Tension Members 84
3.7 Block Shear 85
3.8 Problems for Solution 94
CHAPTER 4 Design of Tension Members 103
4.1 Selection of Sections 103
4.2 Built-Up Tension Members 111
4.3 Rods and Bars 115
4.4 Pin-Connected Members 120
4.5 Design for Fatigue Loads 122
4.6 Problems for Solution 125
CHAPTER 5 Introduction to Axially Loaded Compression Members 129
5.1 General 129
5.2 Residual Stresses 132
5.3 Sections Used for Columns 133
5.4 Development of Column Formulas 137
5.5 The Euler Formula 139
5.6 End Restraint and Effective Lengths of Columns 141
5.7 Stiffened and Unstiffened Elements 144
5.8 Long, Short, and Intermediate Columns 145
5.9 Column Formulas 148
5.10 Maximum Slenderness Ratios 150
Contents vii
5.11 Example Problems 150
5.12 Problems for Solution 158
CHAPTER 6 Design of Axially Loaded Compression Members 163
6.1 Introduction 163
6.2 AISC Design Tables 166
6.3 Column Splices 171
6.4 Built-Up Columns 174
6.5 Built-Up Columns with Components
in Contact with Each Other 175
6.6 Connection Requirements for Built-Up Columns
Whose Components Are in Contact with Each Other 176
6.7 Built-Up Columns with Components not
in Contact with Each Other 182
6.8 Single-Angle Compression Members 187
6.9 Sections Containing Slender Elements 189
6.10 Flexural-Torsional Buckling of Compression Members 191
6.11 Problems for Solution 196
CHAPTER 7 Design of Axially Loaded Compression Members (Continued)
and Colnmn Base Plates 200
7.1 Introduction 200
7.2 Further Discussion of Effective Lengths 201
7.3 Frames Meeting Alignment Chart Assumptions 205
7.4 Frames Not Meeting Alignment Chart Assumptions
as to Joint Rotations 208
7.5 Stiffness-Reduction Factors 211
7.6 Columns Leaning on Each Other for In-Plane Design 215
7.7 Base Plates for Concentrically Loaded Columns 218
7.8 Problems for Solution 232
CHAPTER 8 Introduction to Beams 237
8.1 Types of Beams 237
8.2 Sections Used as Beams 237
8.3 Bending Stresses 238
8.4 Plastic Hinges 239
8.5 Elastic Design 240
8.6 The Plastic Modulus 240
8.7 Theory of Plastic Analysis 243
8.8 The Collapse Mechanism 244
8.9 The Virtual-Work Method 245
viii Contents
8.10 Location of Plastic Hinge for Uniform Loadings 249
8.11 Continuous Beams 250
8.12 Building Frames 252
8.13 Problems for Solution 254
CHAPTER 9 Design of Beams for Moments 263
9.1 Introduction 263
9.2 Yielding Behavior-Full Plastic Moment, Zone 1 266
9.3 Design of Beams, Zone 1 267
9.4 Lateral Support of Beams 275
9.5 Introduction to Inelastic Buckling, Zone 2 277
9.6 Moment Capacities, Zone 2 281
9.7 Elastic Buckling, Zone 3 283
9.8 Design Charts 285
9.9 Noncompact Sections 290
9.10 Problems for Solution 295
CHAPTER 10 Design ofBeams-Miscellaneons Topics (Shear, Deflection, etc.) 302
10.1 Design of Continuous Beams 302
10.2 Shear 304
10.3 Deflections 310
10.4 Webs and Flanges with Concentrated Loads 316
10.5 Unsymmetrical Bending 324
10.6 Design of Purlins 327
10.7 The Shear Center 330
10.8 Beam-Bearing Plates 335
10.9 Lateral Bracing at Member Ends Supported on Base Plates 339
10.10 Problems for Solution 340
CHAPTER 11 Bending and Axial Force 346
11.1 Occurrence 346
11.2 Members Subject to Bending and Axial Tension 347
11.3 First-Order and Second-Order Moments for Members
Subject to Axial Compression and Bending 350
11.4 Direct Analysis Method (DAM) 352
11.5 Effective Length Method (ELM) 353
11.6 Approximate Second-Order Analysis 354
11.7 Beam-Columns in Braced Frames 359
11.8 Beam-Columns in Unbraced Frames 371
11.9 Design of Beam-Columns-Braced or Unbraced 378
11.10 Problems for Solution 386
Contents ix
CHAPTER 12 Bolted Connections 390
12.1 Introduction 390
12.2 Types of Bolts 390
12.3 History of High-Strength Bolts 391
12.4 Advantages of High-Strength Bolts 392
12.5 Snug-Tight, Pretensioned, and Slip-Critical Bolts 392
12.6 Methods for Fully Pretensioning High-Strength Bolts 396
12.7 Slip-Resistant Connections and Bearing-Type Connections 398
12.8 Mixed Joints 399
12.9 Sizes of Bolt Holes 400
12.10 Load Transfer and Types of Joints 401
12.11 Failure of Bolted Joints 404
12.12 Spacing and Edge Distances of Bolts 405
12.13 Bearing-Type Connections-Loads Passing Through
Center of Gravity of Connections 408
12.14 Slip-Critical Connections-Loads Passing Through
Center of Gravity of Connections 419
12.15 Problems for Solution 423
CHAPTER 13 Eccentrically Loaded Bolted Connections and Historical Notes on Rivets 430
13.1 Bolts Subjected to Eccentric Shear 430
13.2 Bolts Subjected to Shear and Tension
(Bearing-Type Connections) 444
13.3 Bolts Subjected to Shear and Tension
(Slip-Critical Connections) 447
13.4 Tension Loads on Bolted Joints 448
13.5 Prying Action 451
13.6 Historical Notes on Rivets 454
13.7 Types of Rivets 455
13.8 Strength of Riveted Connections-Rivets
in Shear and Bearing 457
13.9 Problems for Solution 461
CHAPTER 14 Welded Connections 469
14.1 General 469
14.2 Advantages of Welding 470
14.3 American Welding Society 471
14.4 Types of Welding 471
14.5 Prequalified Welding 475
14.6 Welding Inspection 475
14.7 Classification of Welds 478