Contenido Design of Welded Steel Structures: Principles and Practice

Features

• Provides a solid foundation of theoretical and practical knowledge necessary for the design of welded steel structures

- Discusses arc welding technology, commonly used welded joints, welded joint quality, and welded steel structure economy

• Includes detailed bibliographies at the end of each chapter

Summary

Design of Welded Steel Structures: Principles and Practice provides a solid foundation of theoretical and practical knowledge necessary for the design of welded steel structures. The book begins by explaining the basics of arc welding, describing the salient features of modern arc welding processes as well as the types and characteristics of welded joints, their common defects, and recommended remedial measures. The text then:

• Addresses the analysis and design of welded structures

• Explores the design of joints in respect to common welded steel structures

• Identifies the cost factors involved in welded steelwork

Design of Welded Steel Structures: Principles and Practice draws not only from the author’s own experience, but also from the vast pool of research conducted by distinguished engineers around the globe. Detailed bibliographies are included at the end of each chapter.



Contents

Preface

Author

1. Electric Arc Welding Processes

1.1 Introduction
1.2 Manual Metal Arc Welding
1.3 Metal-Active Gas Welding
1.4 Submerged Arc Welding
1.5 Stud Welding
1.6 Control of Welding Parameters
1.7 Selection Criteria of Welding Process
    1.7.1 Costs
    1.7.2 Location of the Work
    1.7.3 Welding Position
    1.7.4 Access
    1.7.5 Composition of Steel
    1.7.6 Availability of Welding Consumables
    1.7.7 Availability of Skilled Welders
1.8 Safety Aspects

2. Welded Joints

2.1 Introduction
2.2 Types of Welds
    2.2.1 Fillet Weld
    2.2.2 Butt Weld.
2.3 Types of Welded Joints
    2.3.1 Butt Joints
    2.3.2 Tee Joints
    2.3.3 Corner Joints
    2.3.4 Lap Joints
2.4 Heat-Affected Zone
    2.4.1 Chemical Composition of Steel
    2.4.2 Rate of Cooling
2.5 Interacting Variables
    2.5.1 Composition of the Parent Metal, Electrode, and Flux
    2.5.2 Welding Process
    2.5.3 Environment
    2.5.4 Speed of Welding
    2.5.5 Thermal Cycle of Weld
    2.5.6 Size and Type of Joint
    2.5.7 Manipulation of Electrodes
2.6 Residual Stresses
    2.6.1 Heat Treatment

3. Defects in Welded Joints

3.1 Introduction
3.2 Defects in Welds
    3.2.1 Undercut
    3.2.2 Porosity.
    3.2.3 Slag Inclusion
    3.2.4 Pin Holes
    3.2.5 Incomplete Root Penetration
    3.2.6 Lack of Fusion.
    3.2.7 Solidification Cracks
    3.2.8 Defective Weld Profile
    3.2.9 Issues Related to Defects in Welds
        3.2.9.1 Discontinuity in the Load Path
        3.2.9.2 Stress Concentration.
3.3 Defects in HAZ
    3.3.1 Hydrogen Cracking or Cold Cracking
    3.3.2 Lamellar Tearing
3.4 Concluding Remarks

4. Control of Welding Distortion

4.1 Introduction
4.2 Basic Causes of Distortion
    4.2.1 Properties of Materials
    4.2.2 Inherent Stresses in Parent Material
    4.2.3 Uneven Heating
    4.2.4 Restraint during Welding.
4.3 Types of Distortion
4.4 Control of Distortion
    4.4.1 Prevention of Distortion
        4.4.1.1 Design Stage
        4.4.1.2 Fabrication Stage
    4.4.2 Correction after Fabrication
        4.4.2.1 Mechanical Means
        4.4.2.2 Correction by Heating
4.5 Concluding Remarks

5. Brittle Fracture

5.1 Introduction
5.2 Factors Influencing Brittle Fracture
    5.2.1 Metallurgical Feature
    5.2.2 Temperature of Steel in Service
    5.2.3 Service Conditions
5.3 Prevention of Brittle Fracture.
    5.3.1 Selection of Appropriate Steel Material
    5.3.2 Design of Details.
    5.3.3 Quality Control during Fabrication
5.4 Learning from Failures
5.5 Concluding Remarks

6. Quality Control and Inspection      

6.1 Introduction
6.2 Documentation
6.3 Materials
6.4 Welding Procedure
6.5 Skill of Welders and Operators
6.6 Layouts, Templates, Markings, Jigs, and Fixtures
6.7 Weld Preparation, Fit-Up, and Assembly
6.8 Inspection Personnel
6.9 Inspection
    6.9.1 General
    6.9.2 Nondestructive Inspection and Tests
        6.9.2.1 Visual Inspection
        6.9.2.2 Liquid Penetrant Testing
        6.9.2.3 Magnetic Particle Inspection
        6.9.2.4 Radiographic Test
        6.9.2.5 Ultrasonic Test
    6.9.3 Destructive Tests
        6.9.3.1 Chemical Analysis
        6.9.3.2 Metallographic Testing
        6.9.3.3 Mechanical Testing
    6.9.4 Inspection of Trial Assembly
6.10 Concluding Remarks

7. Design Considerations for Welded Joints

7.1 Introduction
7.2 Layout, Locations of Joints, and Make Up of Sections
7.3 Weldability of the Material
7.4 Load Conditions
7.5 Joint Types
7.6 Weld Types
7.7 Weld Size
    7.7.1 Cost.
    7.7.2 Residual Stresses and Distortion
7.8 Edge Preparations
7.9 Ease of Fabrication and Inspection.
7.10 Concluding Remarks

8. Design of Welded Joints

8.1 Introduction
8.2 Butt Weld
    8.2.1 Full Penetration Butt Weld
    8.2.2 Partial Penetration Butt Weld
    8.2.3 Effective Length
    8.2.4 Intermittent Butt Weld
8.3 Fillet Weld.
    8.3.1 Types of Fillet Welds
        8.3.1.1 Normal Fillet Weld
        8.3.1.2 Deep Penetration Fillet Weld
    8.3.2 Size of Fillet Weld
    8.3.3 Effective Throat Thickness
    8.3.4 Effective Length
    8.3.5 Strength of Fillet Weld
    8.3.6 Design Procedure
    8.3.7 End Return.
    8.3.8 Lap Joint in End Connection
        8.3.8.1 Longitudinal Fillet Weld
        8.3.8.2 Transverse Fillet Weld.
    8.3.9 Combined Stresses in Fillet Weld.
    8.3.10 Packing in Fillet Welded Joint
    8.3.11 Bending about a Single Fillet
    8.3.12 Fillet Weld in Compression
    8.3.13 Intermittent Fillet Weld
    8.3.14 Analysis of Typical Fillet Welded Eccentric Connections.
        8.3.14.1 Load Lying in the Plane of the Weld
        8.3.14.2 Load Not Lying in the Plane of Welds
    8.3.15 Fillet Welds in Slots or Holes
8.4 Concluding Remarks

9. Fatigue in Welded Joints

9.1 Introduction
9.2 Fatigue Crack
    9.2.1 Causes of Fatigue Crack.
        9.2.1.1 Stress Concentration
        9.2.1.2 Intrusions
    9.2.2 Crack Growth Rate
9.3 Design
    9.3.1 Implications on Design
    9.3.2 Design Method
9.4 Environmental Effects
9.5 Prevention of Fatigue Cracks.
9.6 Improvement of Welded Joints
    9.6.1 Grinding
    9.6.2 Peening
    9.6.3 Dressing
9.7 Concluding Remarks
Bibliography

10. Beams and Columns

10.1 Introduction
10.2 Beams
    10.2.1 Beam Sections.
    10.2.2 Splices in Beams
10.3 Columns
    10.3.1 Column Sections
    10.3.2 Eccentrically Loaded Columns
    10.3.3 Column Weld Details
    10.3.4 Column Splices
    10.3.5 Column Bases
         10.3.5.1 Pinned-Type Base
         10.3.5.2 Rigid-Type Base
    10.3.6 Column Caps
10.4 Connections.
    10.4.1 Types of Connections
         10.4.1.1 Simple Connection
         10.4.1.2 Rigid Connection
         10.4.1.3 Semi-Rigid Connection
    10.4.2 Design Considerations.
    10.4.3 Beam-to-Beam Simple Connection
    10.4.4 Beam-to-Beam Rigid Connection.
    10.4.5 Beam-to-Column Simple Connection
    10.4.6 Beam-to-Column Rigid Connection
10.5 Castellated Beam

11. Plate Girders

11.1 Introduction
11.2 Flanges.
    11.2.1 Variation in the Thickness of the Flange
    11.2.2 Variation in the Width of the Flange
11.3 Web
11.4 Web-to-Flange Welds
11.5 Transverse Stiffeners
   11.5.1 Intermediate Stiffeners
   11.5.2 Load Bearing Stiffeners
11.6 Stiffener-to-Web Welds
11.7 Stiffener-to-Flange Welds.
   11.7.1 Load Bearing Stiffeners
   11.7.2 Intermediate Stiffeners
11.8 Splices
   11.8.1 Shop Splices
   11.8.2 Site Splices

12. Portal Frames

12.1 Introduction
12.2 Types of Portal Frames
12.3 Knee and Apex Joints
   12.3.1 Simple Joints
   12.3.2 Haunched Joints
12.4 Rafter Site Joints.
12.5 Bases

13. Trusses and Lattice Girders Using Rolled Sections.

13.1 Introduction
13.2 Typical Usage
13.3 Advantages of Welded Roof Truss
13.4 Truss Types and Characteristics
13.5 Analysis
     13.5.1 Primary Stresses.
     13.5.2 Secondary Stresses
          13.5.2.1 Loads Applied between Intersection Points
          13.5.2.2 Eccentricity at Connections
          13.5.2.3 Joint Rigidity and Truss Deflection
          13.5.2.4 Torsional Moment
     13.5.3 Rationale of Analysis
13.6 Connections
     13.6.1 Design Methodology
     13.6.2 Design Criteria
     13.6.3 Types of Connections
          13.6.3.1 Internal Joints
          13.6.3.2 Site Splices
          13.6.3.3 Support Connections
          13.6.3.4 Bracing Connections
     13.6.4 Internal Joints
          13.6.4.1 Transmission of Forces in Chords
          13.6.4.2 Connection Arrangements between Main Members and Web Members
          13.6.4.3 Spacer Plates
     13.6.5 Site Splices
     13.6.6 Support Connections
     13.6.7 Bracing Connections

14. Trusses and Lattice Girders Using Hollow Sections

14.1 Introduction
14.2 Typical Examples
14.3 Advantages
14.4 Types of Hollow Sections.
14.5 Material Quality
14.6 Connections
14.7 Structural Analysis and Design Parameters
14.8 Local Stress Distribution
     14.9.1 Chord Face Deformation.
     14.9.2 Chord Side-Wall Buckling/Yielding
     14.9.3 Chord Shear
     14.9.4 Chord Punching Shear
     14.9.5 Web Member Failure
     14.9.6 Localized Buckling
14.10 Joint Capacity
14.11 Joint Reinforcement
14.12 Typical Joint Details.
14.13 Economy in Fabrication

15. Orthotropic Floor System

15.1 Introduction
15.2 Advantages.
     15.2.1 Savings in Weight of the Structure
     15.2.2 Reduction in Seismic Forces
     15.2.3 Saving in Substructure
     15.2.4 Ease of Erection
     15.2.5 Saving due to Reduction of the Depth of the Structure.
15.3 Structural Behavior
15.4 Analysis.
15.5 Typical Details
     15.5.1 Longitudinal Ribs
     15.5.2 Transverse Cross Girders
     15.5.3 Splices of Longitudinal Ribs
     15.5.4 Site Splices of Panels
15.6 Distortion
15.7 Corrosion Protection

16. Economy in Welded Steelwork

16.1 Introduction
16.2 Mechanics of Costing
   16.2.1 Direct Costs
        16.2.1.1 Labor Cost
        16.2.1.2 Costs of Consumables
   16.2.2 Indirect Costs
16.3 Factors Affecting Welding Costs
   16.3.1 Design Stage
        16.3.1.1 Choice of Sections
        16.3.1.2 Welding Position
        16.3.1.3 Accessibility of Welds
        16.3.1.4 Joint Preparation and Weld Volume
   16.3.2 Fabrication Stage
        16.3.2.1 Rectification of Mistakes
        16.3.2.2 Accuracy of Edge Preparation and Fit-Up
        16.3.2.3 Jigs and Manipulators
        16.3.2.4 Choice of Welding Process
   16.3.3 General Remarks
        16.3.3.1 Overheads
        16.3.3.2 Labor Costs
16.4 Concluding Remarks
Bibliography
Index.