Structural Steel Design to Eurocode 3 and AISC Specifications

Claudio Bernuzzi, Benedetto Cordova

• Publisher: Wiley-Blackwell
• Year: 2016
• ISBN:
  9781118631270
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Civil Engineering
• Index: Technology & Engineering

Structural Steel Design to Eurocode 3 and AISC Specifications deals with the theory and practical applications of structural steel design in Europe and the USA. The book covers appropriate theoretical and background information, followed by a more design?oriented coverage focusing on European and United States specifications and practices, allowing the reader to directly compare the approaches and results of both codes. Chapters follow a general plan, covering: •A general section covering the relevant topics for the chapter, based on classical theory and recent research developments •A detailed section covering design and detailing to Eurocode 3 specification •A detailed section covering design and detailing to AISC specifications Fully worked examples are using both codes are presented. With construction companies working in increasingly international environments, engineers are more and more likely to encounter both codes. Written for design engineers and students of civil and structural engineering, this book will help both groups to become conversant with both code systems.

CHAPTER 1
The Steel Material

1.1 General Points about the Steel Material

The term steel refers to a family of iron–carbon alloys characterized by well-defined percentage ratios of main individual components. Specifically, iron–carbon alloys are identified by the carbon (C) content, as follows:

• wrought iron, if the carbon content (i.e. the percentage content in terms of weight) is higher than 1.7% (some literature references have reported a value of 2%);
• steel, when the carbon content is lower than the previously mentioned limit. Furthermore, steel can be classified into extra-mild (C < 0.15%), mild (C = 0.15 ÷ 0.25%), semi-hard (C = 0.25 ÷ 0.50%), hard (C = 0.50 ÷ 0.75%) and extra-hard (C > 0.75%) materials.

Structural steel, also called constructional steel or sometimes carpentry steel, is characterized by a carbon content of between 0.1 and 0.25%. The presence of carbon increases the strength of the material, but at the same time reduces its ductility and weldability; for this reason structural steel is usually characterized by a low carbon content. Besides iron and carbon, structural steel usually contains small quantities of other elements. Some of them are already present in the iron ore and cannot be entirely eliminated during the production process, and others are purposely added to the alloy in order to obtain certain desired physical or mechanical properties.

Among the elements that cannot be completely eliminated during the production process, it is worth mentioning both sulfur (S) and phosphorous (P), which are undesirable because they decrease the material ductility and its weldability (their overall content should be limited to approximately 0.06%). Other undesirable elements that can reduce ductility are nitrogen (N), oxygen (O) and hydrogen (H). The first two also affect the strain-ageing properties of the material, increasing its fragility in regions in which permanent deformations have taken place.

The most important alloying elements that may be added to the materials are manganese (Mn) and silica (Si), which contribute significantly to the improvement of the weldability characteristics of the material, at the same time increasing its strength. In some instances, chromium (Cr) and nickel (Ni) can also be added to the alloy; the former increases the material strength and, if is present in sufficient quantity, improves the corrosion resistance (it is used for stainless steel), whereas the latter increases the strength while reduces the deformability of the material.

Steel is characterized by a symmetric constitutive stress-strain law (σ–ε). Usually, this law is determined experimentally by means of a tensile test performed on coupons (samples) machined from plate material obtained from the sections of interest (Section 1.7). Figure 1.1 shows a typical stress-strain response to a uniaxial tensile force for a structural steel coupon. In particular, it is possible to distinguish the following regions:

• an initial branch that is mostly linear (elastic phase), in which the material shows a linear elastic behaviour approximately up to the yielding stress (f_y). The strain corresponding to f_y is usually indicated with ε_y (yielding strain). The slope of this initial branch corresponds to the modulus of elasticity of the material (also known as longitudinal modulus of elasticity or Young’s modulus), usually indicated by E, with a value between 190 000 and 210 000 N/mm² (from 27 560 to 30 460 ksi, approximately);
• a plastic phase, which is characterized by a small or even zero slope in the σ–ε reference system;
• the ensuing branch is the hardening phase, in which the slope is considerably smaller when compared to the elastic phase, but still sufficient enough to cause an increase in stress when strain in...

Table of contents

• Cover
• Title Page
• Table of Contents
• Preface
• CHAPTER 1: The Steel Material
• CHAPTER 2: References for the Design of Steel Structures
• CHAPTER 3: Framed Systems and Methods of Analysis
• CHAPTER 4: Cross-Section Classification
• CHAPTER 5: Tension Members
• CHAPTER 6: Members in Compression
• CHAPTER 7: Beams
• CHAPTER 8: Torsion
• CHAPTER 9: Members Subjected to Flexure and Axial Force
• CHAPTER 10: Design for Combination of Compression, Flexure, Shear and Torsion
• CHAPTER 11: Web Resistance to Transverse Forces
• CHAPTER 12: Design Approaches for Frame Analysis
• CHAPTER 13: The Mechanical Fasteners
• CHAPTER 14: Welded Connections
• CHAPTER 15: Connections
• CHAPTER 16: Built-Up Compression Members
• Appendix A: Conversion Factors
• Appendix B: References and Standards
• Index
• End User License Agreement