Basic Theory of Plates and Elastic Stability - Part 7

Tài liệu tham khảo giáo trình cơ học kết cấu trong ngành xây dựng bằng Tiếng Anh - Yamaguchi, E. “Basic Theory of Plates and Elastic Stability” Structural Engineering Handbook Ed. Chen Wai-Fah Boca Raton: CRC Press LLC, 1999 - Cold-Formed Steel Structures
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Basic Theory of Plates and Elastic Stability - Part 7Yu, W.W. “Cold-Formed Steel Structures”Structural Engineering HandbookEd. Chen Wai-FahBoca Raton: CRC Press LLC, 1999 Cold-Formed Steel Structures 7.1 Introduction 7.2 Design Standards 7.3 Design Bases Allowable Stress Design (ASD) • Limit States Design or Load and Resistance Factor Design (LRFD) 7.4 Materials and Mechanical Properties Yield Point, Tensile Strength, and Stress-Strain Relationship • Strength Increase from Cold Work of Forming • Modulus of Elasticity, Tangent Modulus, and Shear Modulus • Ductility 7.5 Element Strength Maximum Flat-Width-to-Thickness Ratios • Stiffened Ele- ments under Uniform Compression • Stiffened Elements with Stress Gradient • Unstiffened Elements under Uniform Com- pression • Uniformly Compressed Elements with an Edge Stiff- ener • Uniformly Compressed Elements with Intermediate Stiffeners 7.6 Member Design Sectional Properties • Linear Method for Computing Sectional Properties • Tension Members • Flexural Members • Concen- trically Loaded Compression Members • Combined Axial Load and Bending • Cylindrical Tubular Members 7.7 Connections and Joints Welded Connections • Bolted Connections • Screw Connec- tions 7.8 Structural Systems and Assemblies Metal Buildings • Shear Diaphragms • Shell Roof Structures • Wall Stud Assemblies • Residential Construction • Composite ConstructionWei-Wen Yu 7.9 Defining TermsDepartment of Civil Engineering, ReferencesUniversity of Missouri-Rolla, Further ReadingRolla, MO7.1 IntroductionCold-formed steel members as shown in Figure 7.1 are widely used in building construction, bridgeconstruction, storage racks, highway products, drainage facilities, grain bins, transmission towers,car bodies, railway coaches, and various types of equipment. These sections are cold-formed fromcarbon or low alloy steel sheet, strip, plate, or flat bar in cold-rolling machines or by press brake orbending brake operations. The thicknesses of such members usually range from 0.0149 in. (0.378mm) to about 1/4 in. (6.35 mm) even though steel plates and bars as thick as 1 in. (25.4 mm) can becold-formed into structural shapes. 1999 by CRC Press LLCcFIGURE 7.1: Various shapes of cold-formed steel sections. (From Yu, W.W. 1991. Cold-Formed SteelDesign, John Wiley & Sons, New York. With permission.) The use of cold-formed steel members in building construction began in the 1850s in both the U.S.and Great Britain. However, such steel members were not widely used in buildings in the U.S. untilthe 1940s. At the present time, cold-formed steel members are widely used as construction materialsworldwide. Compared with other materials such as timber and concrete, cold-formed steel members can offerthe following advantages: (1) lightness, (2) high strength and stiffness, (3) ease of prefabrication andmass production, (4) fast and easy erection and installation, and (5) economy in transportation andhandling, just to name a few. From the structural design point of view, cold-formed steel members can be classified into twomajor types: (1) individual structural framing members (Figure 7.2) and (2) panels and decks(Figure 7.3). In view of the fact that the major function of the individual framing members is to carry load,structural strength and stiffness are the main considerations in design. The sections shown inFigure 7.2 can be used as primary framing members in buildings up to four or five stories in height.In tall multistory buildings, the main framing is typically of heavy hot-rolled shapes and the secondaryelements such as wall studs, joists, decks, o ...