Design of Steel Structures

Luís Simões da Silva is Professor of Steel Construction at the Civil Engineering Dept. of the University of Coimbra/ Portugal, where he is responsible for the Steel and Mixed Building Technologies Research Centre. He is President of the Portuguese Steelwork Association (CMM) and member of the Executive Board and President of the Technical Management Board of the ECCS. He has authored over 300 scientific articles in this field. Rui A. D. Simões is Professor at the Civil Engineering Dept. of the University of Coimbra/ Portugal, where he got his BSc in 1990, his MSc in 1995 and his PhD in 2000. He is heavily involved in experimental research work and teaching of steel related courses in the BSc, MSc, PhD and continues education programs. Helena Gervásio is Visiting Professor at the Civil Engineering Department of the University of Coimbra/ Portugal. She is Technical Director of the GIPAC Lda., an engineering consultancy company specialized in structural engineering. She is member of the Technical Committee TC14-Sustainability of ECCS.

Luís Simões da Silva ist Professor für Stahlbau im Fachbereich Bauwesen der Universität Coimbra, Portugal, und Leiter des Forschungszentrum für Stahl- und Mischbautechnologie. Er ist Präsident des portugiesischen Stahlbauverbandes (CMM), Vorstandsmitglied und Vorsitzender des Technical Management Board der EKS und Autor von über 300 wissenschaftlichen Abhandlungen in seinem Fachgebiet. Rui A. D. Simões ist Professor im Fachbereich Bauwesen der Universität Coimbra, Portugal. Im Jahr 1990 machte er dort seinen Abschluss als Bachelor of Science. Der Master-Grad wurde ihm 1995 verliehen und er promovierte im Jahr 2000. Professor Simões ist vornehmlich in der experimentellen Forschung tätig. Als Dozent unterrichtet er Studenten in Bachelor- und Master-Studiengängen und betreut Doktoranden. Weiterhin ist er für die Weiterentwicklung von Ausbildungsprogrammen zuständig. Helena Gervásio ist Gastprofessorin im Fachbereich Bauwesen der Universität Coimbra, Portugal, technische Direktorin von GIPAC Lda, ein Ingenieurbüro mit Spezialisierung auf Beratungsleistungen im Bereich Stahlbautechnik. Sie ist Mitglied des technischen Ausschusses TC14 "Sustainability and Eco-Efficiency of Steel Construction" der EKS.

FOREWORD xiii

PREFACE xv

Chapter 1 INTRODUCTION 1

1.1. General Observations 1

1.2. Codes of Practice and Normalization 3

1.2.1. Introduction 3

1.2.2. Eurocode 3 6

1.2.3. Other standards 7

1.3. Basis of Design 8

1.3.1. Basic concepts 8

1.3.2. Reliability management 9

1.3.3. Basic variables 13

1.3.4. Ultimate limit states 15

1.3.5. Serviceability limit states 16

1.3.6. Durability 18

1.3.7. Sustainability 19

1.4. Materials 21

1.4.1. Material specification 21

1.4.2. Mechanical properties 22

1.4.3. Toughness and through thickness properties 25

1.4.4. Fatigue properties 27

1.4.5. Corrosion resistance 27

1.5. Geometric Characteristics and Tolerances 28

Chapter 2 STRUCTURAL ANALYSIS 33

2.1. Introduction 33

2.2. Structural Modelling 34

2.2.1. Introduction 34

2.2.2. Choice of member axis 36

2.2.3. Influence of eccentricities and supports 38

2.2.4. Non-prismatic members and members with curved axis 39

2.2.5. Influence of joints 44

2.2.6. Combining beam elements together with two and three dimensional elements 51

2.2.7. Worked examples 52

2.3. Global Analysis of Steel Structures 75

2.3.1. Introduction 75

2.3.2. Structural stability of frames 77

2.3.3. Imperfections 87

2.3.4. Worked example 93

2.4. Classification of Cross Sections 108

Chapter 3 DESIGN OF MEMBERS 115

3.1. Introduction 115

3.1.1. General 115

3.1.2. Resistance of cross sections 116

3.1.3. Buckling resistance of members 121

3.2. Tension 121

3.2.1. Behaviour in tension 121

3.2.2. Design for tensile force 123

3.2.3. Worked examples 126

3.3. Laterally Restrained Beams 134

3.3.1. Introduction 134

3.3.2. Design for bending 135

3.3.3. Design for shear 139

3.3.4. Design for combined shear and bending 140

3.3.5. Worked examples 142

3.4. Torsion 154

3.4.1. Theoretical background 154

3.4.2. Design for torsion 164

3.4.3. Worked examples 166

3.5. Compression 172

3.5.1. Theoretical background 172

3.5.2. Design for compression 183

3.5.3. Worked examples 188

3.6. Laterally Unrestrained Beams 197

3.6.1. Introduction 197

3.6.2. Lateral-torsional buckling 197

3.6.3. Lateral-torsional buckling resistance 210

3.6.4. Worked examples 214

3.7. Beam-Columns 223

3.7.1. Introduction 223

3.7.2. Cross section resistance 224

3.7.2.2. Design resistance 227

3.7.3. Buckling resistance 230

3.7.4. Worked examples 242

Chapter 4 ELASTIC DESIGN OF STEEL STRUCTURES 271

4.1. Introduction 271

4.2. Simplified Methods of Analysis 273

4.2.1. Introduction 273

4.2.2. Amplified sway-moment method 275

4.2.3. Sway-mode buckling length method 277

4.2.4. Worked example 278

4.3. Member Stability of Non-prismatic Members and Components 288

4.3.1. Introduction 288

4.3.2. Non-prismatic members 288

4.3.3. Members with intermediate restraints 293

4.3.4. General method 299

4.3.5. Worked example 302

4.4. Design Example 1: Elastic Design of Braced Steel-Framed Building 317

4.4.1. Introduction 317

4.4.2. Description of the structure 318

4.4.3. General safety criteria, actions and combinations of actions 321

4.4.4. Structural analysis 335

4.4.5. Design checks 339

Chapter 5 PLASTIC DESIGN OF STEEL STRUCTURES 343

5.1. General Rules for Plastic Design 343

5.1.1. Introduction 343

5.1.2. Plastic limit analysis: method of mechanisms 344

5.1.3. Code requirements for plastic analysis 349

5.2. Methods of Analysis 352

5.2.1. Introduction 352

5.2.2. Approximate methods for pre-design 352

5.2.3. Computational analysis 364

5.2.4. 2nd order effects 369

5.2.5. Worked example 375

5.3. Member Stability and Buckling Resistance 385

5.3.1. Introduction 385

5.3.2. General criteria for the verification of the stability of members with plastic hinges 385

5.3.3. Bracings 386

5.3.4. Verification of the stability of members with plastic hinges 389