[...]... centerline of flange to tip of stem, l1, l2 are the length of the legs of the angle, t1, t2 are the thickness of the legs of the angle, bf is the flange width, tf is the average thickness of flange, tw is the thickness of web, Ic is the moment of inertia of compression flange taken about the axis of the web, It is the moment of inertia of tension flange taken about the axis of the web, and Ix is the moment of inertia... Equation 1.17, the design strength of the section is 2 fc Pn ¼ 0:85b67:2ð0:6581:02 Þ50c ¼ 1848 kip 1-24 Principles of Structural Design Determine the design strength for the built-up section: The built-up section is expected to possess a design strength that is 20% in excess of the design strength of the W24 Â 229 section, so ðfc Pn Þreq’d ¼ ð1:20Þð1848Þ ¼ 2218 kip Determine the size of the cover plates:... defined in the footnote of Table 1.4, E is the modulus of elasticity, Fy is the specified minimum yield stress, b is the width of the component element, and t is the thickness of the component element 1-22 Principles of Structural Design TABLE 1.7 Formula for Qa Qs ¼ effective area actual area The effective area is equal to the summation of the effective areas of the stiffened elements of the cross-section...1-2 Principles of Structural Design 1.1 Materials 1.1.1 Stress–Strain Behavior of Structural Steel Structural steel is a construction material that possesses attributes such as strength, stiffness, toughness, and ductility that are desirable in modern constructions Strength is the ability of a material to resist stress It is measured in terms of the material’s yield strength... (Fy) or tensile stress (Fu) of the material divided by a factor of safety The factor of safety is introduced to account for the effects of overload, understrength, and approximations used in structural analysis The general format for an allowable stress design has the form m Rn X ! Qni FS i¼1 ð1:2Þ where Rn is the nominal resistance of the structural component expressed in unit of stress (i.e., the allowable... element of the built-up cross-section, rib is the radius of gyration of individual component relative to its centroidal axis parallel to the axis of buckling of the member, and h is the distance between centroids of components elements measured perpendicularly to the buckling axis of the built-up member No modification to (KL=r) is necessary if the buckling axis is perpendicular to the planes of contact of. .. cross-sections 1-18 Principles of Structural Design TABLE 1.4 Limiting Width–Thickness Ratios for Compression Elements Under Pure Compression Flanges of I-shaped sections; plates projecting from compression elements; outstanding legs of pairs of angles in continuous contact; flanges of channels b=t Limiting value, lr pffiffiffiffiffiffiffiffiffiffi 0:56 E=Fy Flanges of square and rectangular box and HSS of uniform thickness; flange... for decades for steel design of buildings and bridges It continues to enjoy popularity among structural engineers engaged in steel building design In allowable stress (or working stress) design, member stresses computed under service (or working) loads are compared to some predesignated stresses called allowable stresses The allowable stresses are often expressed as a function of the yield stress (Fy)... of steel The ability of structural steel to deform considerably before failure by fracture allows an indeterminate structure to undergo stress redistribution Ductility also enhances the energy absorption characteristic of the structure, which is extremely important in seismic design 1.1.2 Types of Steel Structural steels used for construction are designated by the American Society of Testing and Materials... edge of the pin hole to the edge of the member measured in the direction of the force, Apb is the projected bearing area ¼ dt, Asf ¼ 2t (a þ d=2), beff ¼ 2t þ 0.63, in (or, 2t þ 16, mm) but not more than the actual distance from the edge of the hole to the edge of the part measured in the direction normal to the applied force, d is the pin diameter, and t is the plate thickness 1-16 Principles of Structural . y0 w0 h0" alt="" PRINCIPLES OF STRUCTURAL DESIGN PRINCIPLES OF STRUCTURAL DESIGN Edited by Wai-Fah Chen Eric M. Lui This material was previously published in the Handbook of Structural Engineering,. Behavior of Structural Steel  Types of Steel  High- Performance Steel  Fireproofing of Steel  Corrosion Protection of Steel  Structural Steel Shapes  Structural Fasteners  Weld- ability of Steel 1.2. high-strength low-alloy structural steel shapes, plates, and bars and quenched and tempered alloy structural steel plates for bridges 1-2 Principles of Structural Design terms of the modulus of elasticity