Ductile Design of Steel Structures

Transcription

1 Ductile Design of Steel Structures Michel Bruneau, Ph.D., P.Eng. Chia-Ming Uang, Ph.D. Rafael Sabelli, S.E. Second Edition Mc Grain/ Hill New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New Delhi San Juan Seoul Singapore Sydney Toronto

2 Contents Preface xvii 1 Introduction 1 References 6 2 Structural Steel Introduction Common Properties. of Steel Materials Engineering Stress-Strain 8 Curve Effect of Temperature on Stress-Strain Curve Effect of Temperature on Ductility and Notch-Toughness Strain Rate Effect on Tensile and Yield Strengths Probable Yield Strength Plasticity, Hysteresis, Bauschinger Effects Metallurgical Process of Yielding, Slip Planes Brittleness in Welded Sections Metallurgical Transformations During Welding, Heat-Affected Zone, Preheating Hydrogen Embrittlement Carbon Equivalent Flame Cutting Weld Restraints Lamellar Tearing Thick Steel Sections Fracture Mechanics Partial Penetration Welds K-Area Fractures Strain Aging Stress Corrosion Corrosion Fatigue Ductility of Corroded Steel Low-Cycle versus High-Cycle. Fatigue High-Cycle Fatigue Low-Cycle Fatigue 62 V

3 vi Contents 2.7 Material Models Rigid Plastic Model Elasto-Plastic Models Power, Ramberg-Osgood, and Menegotto-Pinto Functions Smooth Hysteretic Models 80 of Plastic Material Behavior Advantages 2.9 Self-Study Problems 100 References Plastic Behavior at the Cross-Section Level Ill 3.1 Pure Flexural Yielding Ill Doubly Symmetric Sections Sections Having a Single Axis of Symmetry Impact of Some Factors on Inelastic Flexural Behavior Behavior During Cyclic Loading Combined Flexural and Axial Loading Rectangular Cross-Section Wide-Flange Sections: Strong-Axis Bending Wide-Flange Sections: Weak-Axis Bending Moment-Curvature Relationships Combined Flexural and Shear Loading. 3.4 Combined Flexural, Axial, and 137 Shear Loading Pure Plastic Torsion: Sand-Heap Analogy Review of Important Elastic 145 Analysis Results Sand-Heap Analogy Combined Flexure and Torsion Biaxial Flexure General Principles Fiber Models Composite Sections Self-Study Problems 163 References Concepts of Plastic Analysis Introduction to Simple Plastic Analysis Simple Plastic Analysis Methods Event-to-Event Calculation (Step-by-Step Method) 178

4 Contents vii Equilibrium Method (Statical Method) Kinematic Method (Virtual-Work Method) Theorems of Simple Plastic Analysis Upper Bound Theorem Lower Bound Theorem Uniqueness Theorem Application of" the Kinematic Method Basic Mechanism Types Combined Mechanism Mechanism Analysis by Center of Rotation Distributed Loads Shakedown Theorem (Deflection Stability) Yield Lines General Framework Strength of Connections Plastic Mechanisms of Local Buckling Self-Study Problems 238 References Systematic Methods of Plastic. Analysis Number of Basic Mechanisms Direct Combination of Mechanisms Example: One-Bay, One-Story Frame Example: Two-Story Frame with Overhanging Bay Method of Inequalities Self-Study Problems 266 References Applications of Plastic Analysis Moment Redistribution Design Methods Statical Method of Design Autostress Design Method Capacity Design Concepts Shear Failure Protection Protection Against Column Hinging 284

5 yj Contents 2.7 Material Models Rigid Plastic Model Elasto-Plastic Models Power, Ramberg-Osgood, and Menegotto-Pinto Functions Smooth Hysteretic Models Advantages of Plastic Material Behavior 2.9 Self-Study 94 Problems 100 References Plastic Behavior at the Cross-Section Level Ill 3.1 Ptire Flexural Yielding Ill Doubly Symmetric Sections Sections Having a Single Axis of Symmetry Impact of Some Factors on Inelastic Flexural Behavior Behavior During Cyclic Loading Combined Flexural and Axial Loading Rectangular Cross-Section Wide-Flange Sections: Strong-Axis Bending Wide-Flange Sections: Weak-Axis Bending Moment-Curvature Relationships Combined Flexural and Shear Loading 3.4 Combined Flexural, Axial, and 137 Shear Loading Pure Plastic Torsion: Sand-Heap Analogy Review of Important Elastic 145 Analysis Results Sand-Heap Analogy Combined Flexure and Torsion Biaxial Flexure General Principles Fiber Models Composite Sections Self-Study Problems 163 References Concepts of Plastic Analysis Introduction to Simple Plastic Analysis Simple Plastic Analysis Methods Event-to-Event Calculation (Step-by-Step Method) 178

6 Contents vii Equilibrium Method (Statical Method) Kinematic Method (Virtual-Work Method) Theorems of Simple Plastic Analysis Upper Bound Theorem Lower Bound Theorem Uniqueness Theorem Application of the Kinematic Method Basic Mechanism Types Combined Mechanism Mechanism Analysis by Center of Rotation Distributed Loads Shakedown Theorem (Deflection Stability) Yield Lines General Framework Strength of Connections Plastic Mechanisms of Local Buckling Self-Study Problems 238 References Systematic Methods of Plastic Analysis Number of Basic Mechanisms Direct Combination of Mechanisms Example: One-Bay One-Story Frame Example: Two-Story Frame with Overhanging Bay Method of Inequalities Self-Study Problems 266 References Applications of Plastic Analysis Moment Redistribution Design Methods Statical Method of Design Autostress Design Method Capacity Design Concepts Shear Failure Protection Protection Against Column Hinging 284

7 viii Contents 6.3 Push-Over Analysis Monotonic Push-Over Analysis Cyclic Push-Over Analysis Seismic Design Using Plastic Analysis Global versus Local Ductility Demands Displacement Ductility versus 296 Curvature Ductility Ductility of Yielding Link for Structural Element in Series Displacement Compatibility of Nonductile Systems Self-Study Problems 303 References Building Code Seismic Design Philosophy Introduction Need for Ductility in Seismic Design Elastic Response and Response Spectrum Inelastic Response and Ductility Reduction Collapse Mechanism versus Yield Mechanism Design Earthquake Equivalent Lateral Force Procedure Physical Meaning of Seismic Performance Factors Capacity Design Global-Level Approach Local-Level Approach Performance-Based Seismic Design Framework Seismic Performance Objective USA: ASCE Canada: NBCC Japan: BSL Seismic Design of Tall Buildings Next-Generation Performance-Based 333 Seismic Design Historical Perspective of Seismic Codes 336 References Design of Ductile Moment-Resisting Frames Introduction Historical Developments 346

8 Contents ix General Behavior and Plastic Mechanism Design Philosophy Basic Response of Ductile Moment-Resisting Frames to Lateral Loads Internal Forces During Seismic Response Plastic Rotation Demands Lateral Bracing and Local Buckling Ductile Moment-Frame Column Design Axial Forces in Columns Considerations for Column Splices Strong-Column/Weak-Beam Philosophy Effect of Axial Forces on Column Ductility Panel Zone Flange Yielding/Crippling Prevention.. Distortion and Column Web Forces on Panel Zones Behavior of Panel Zones Modeling of Panel Zone Behavior Design 370 of Panel Zone Beam-to-Column Connections Knowledge and Practice Prior to the 1994 Northridge Earthquake Damage During the Northridge Earthquake Causes for Failures Reexamination of Pre-Northridge Practice Post-Northridge Beam-to-Column Connections Design Strategies for New Buttdings Initial Concepts Post-Northridge Beam-to-Column 412 Prequalified Connections International Relevance Semi-Rigid (Partially Restrained) Bolted Connections Design of a Ductile Moment Frame General Connection Design Issues 450

9 X Contents Welding and Quality Control Issues Generic Design Procedure P-A Stability of Moment Resisting Frames Fundamental Concept and Parameters Impact on Hysteretic Behavior Design Requirements Design Example Building Description and Loading Global Requirements Basis of Design Iterative Analysis and Proportioning Member Checks WUF-W Connection Design Detailing Bracing Completion of Design Self-Study Problems 486 References Design of Ductile Concentrically Braced Frames Introduction Historical Developments General Behavior and Plastic Mechanism Design Philosophy Hysteretic Behavior of Single Braces Brace Physical Inelastic Cyclic Behavior Brace Slenderness Compression Strength Degradation of Brace Under Repeated Loading Brace Compression Overstrength at First Buckling Evolution of Codified Strength and Slenderness Limits Local Buckling Low-Cycle Fatigue Models Models of Single Brace Behavior 535

10 Contents xi 9.3 Hysteretic Behavior and Design of Concentrically Braced Frames System Configuration and General Issues Brace Design Beam Design Column Design Connection Design Other Issues Other Concentric Braced-Frame Systems Special Truss Moment Frames (STMF) Zipper Frames Design Example Building Description and Loading Global Requirements Basis of Design Preliminary Brace Sizing Plastic Mechanism Analysis Capacity Design of Beam Capacity Design of Column Iterative Analysis and Proportioning Connection Design Completion of Design Additional Consideration: Gravity Bias in Seismic Systems Self-Study Problems 579 References Design of Ductile Eccentrically Braced Frames Introduction Historical Development General Behavior and Plastic Mechanism Design Philosophy Link Behavior Stiffened and Unsoffened Links Critical Length for Shear Yielding Classifications of Links and Link Deformation Capacity Link Transverse Stiffener Effect of Axial Force 601

11 xii Contents Effect of Concrete Slab Link Overstrength Qualification Test and Loading Protocol Effect EBF Lateral Stiffness and Strength Elastic Stiffness Link Required Rotation Plastic Analysis and Ultimate Frame Strength Ductility Design Sizing of Links Link Detailing Lateral Bracing of Link Capacity Design of Other Structural Components General Internal Force Distribution Diagonal Braces Beams Outside of Link Columns Connections Design Example Building Description and Loading Global Requirements Basis of Design Sizing of Links Final Link Design Check Link Rotation Link Detailing Completion of Design Self-Study Problems 643 References Design of Ductile Buckling-Restrained Braced Frames Introduction Buckling-Restrained Braced Frames versus Conventional Frames Concept and Components of Buckling-Restrained Brace Development of BRBs Nonductile Failure Modes Steel Casing Brace Connection 662

12 Contents xiii Frame Distortion Effect on Gusset Connection BRBF Configuration Design of Bucklmg-Restrained Braces Brace Design Elastic Modeling Gravity Loads Capacity Design of BRBF AISC Testing Requirements Brace Casing Brace Connections Beams and Columns Nonlinear Modeling Design Example Building Description and Loading Global Requirements Basis of Design Iterative Analysis and Proportioning Brace Validation and Testing Completion of Design Self-Study Problem 686 References Design of Ductile Steel Plate Shear Walls Introduction General Concepts Historical Developments International Implementations Behavior of Steel Plate Shear Walls General Behavior Plastic Mechanism Design Philosophy and Hysteretic Energy Dissipation Analysis and Modeling Strip Models Finite Element Models Demands on HBEs Demands on VBEs Design Introduction Web Plate Design HBE Design VBE Design 750

13 xiv Contents Distribution of Lateral Force Between Frame and Infill Connection Details Design of Openings Perforated Steel Plate Shear Walls Special Perforated Steel Plate Shear Walls Steel Plate Shear Walls with Reinforced Corners Cutouts Design Example Building Description and Loading Global Requirements Basis of Design Web Design HBE Design VBE Design Drift HBE Connection Design Completion of Design Self-Study Problems 780 References Other Ductile Steel Energy Dissipating Systems Structural Fuse Concept Energy Dissipation Through Steel Yielding Early Concepts Triangular Plates in Flexure Tapered Shapes C-Shaped and E-Shaped Devices Energy Dissipation Through Friction Rocking Systems Self-Centering Post-Tensioned Systems Alternative Metallic Materials: Lead, 823 Shape-Memory Alloys, and Others Validation Quantification 827 References 828 of Steel Beams Stability and Rotation Capacity 14.1 Introduction Plate Elastic and Postelastic Buckling Behavior General Description of Inelastic Beam Behavior 845

14 Contents XV Beams with Uniform Bending Moment Beams with Moment Gradient Comparison of Beam Behavior Under Uniform Moment and Moment Gradient Inelastic Flange Local Buckling Modeling Assumptions Buckling of an Orthotopic Plate Torsional Buckling of a Restrained Rectangular Plate Web Local Buckling Inelastic Lateral-Torsional Buckling General Beam Under Uniform Moment Beam Under Moment Gradient Code Comparisons Interaction of Beam Buckling Modes Cyclic Beam Buckling Behavior Self-Study Problem 888 References 888 Index 891