Chapter 9, Problem 9.2PFS

If the beam in Problem 5.5-9 i5 braced at A, B, and C, compute for the unbr Cb aced length AC (same as Cb for unbraced length CB). Do not include the beam weight in the loading. a. Use the unfactored service loads. b. Use factored loads.

For the Integrated Project (office building), design the Floor Girders in the gravity-only system, assuming that the top flange is fully restrained with the floor diaphragm. 1. Use Table 3-2 from the Steel Manual to select the most economical compact W-shape section. Demands: Stories 1 and 2 Edge: 114.4 k.ft From Table 3-2, use W12x50 D/C = should be less than 0.95: D/C = Stories 1 and 2 Interior: 226.4 k.ft Use W12x50: D/C = Roof Edge: 33.3 k.ft Use W12x40: D/C = Roof Interior: 58.4 k.ft Use W12x40: D/C =

A built-up member is used as a column having a length of 20 ft. Assume the member is hinged at the top and at the bottom for buckling in either principal direction. Using A36 steel, determine the axial compressive strength (ASD & LRFD).   USE NSCP 2015/ AISC REQUIREMENTS.

Use NSCP 2015. The beam shown has continuous lateral support of both flanges. The uniform load consisting of 50% dead load and 50% live load. The dead load includes the weight of the beam. Used grade 50 steel. 6 k/ft |--0-0²- -18'-0"- fo 4-6- -6'-0" 1. Considering LRFD. Which of the following most nearly gives the design load Wu? 2. Considering LRFD. Which of the following most nearly gives the maximum negative design moment, Mu in ft-kips? 3. Considering W12x35 beam section, The section is 4. Considering ASD the W12x35 beam section, Which of the following most nearly gives allowable strength in ft-kips

5.5-3 A simplrted beam is subjected to a uniform service dead load of 1.0 kip cluding the weight of the beam), a uniform service live load of 0 kipft, and a concentrated service dead load of 40 kips. The beam feet long, and the concentrated load is located 15 feet from the left The beam has continuous lateral support, and A572 Grade 50 steel is used. Is a W30 x 108 adequate a. Use LRFD. b. Use ASD.

The built-up girder below is comprised of four A572 Grade 50 plates welded together. Compute the section modulus (S), plastic modulus (Z₁), and shape factor (Z₁/S). Using Table B41.b of the Specification, determine whether the flanges and web are compact, noncompact, or slender. -PL 1" x 40" 10" CLEAR SPACING PL 1.5" x 20" TYP

PLATE #3 PROBLEM: A built up section of A992 steel is made from plates fully welded together. The flanges consist of PL16x380 and PL12x500 for the web. Check the beam for flexure. Total load Deflection is limited to L/240. Cite all applicable specifications you used to solve the problem from NSCP 2015. 1. For full lateral support 2. For Lateral bracing at supports and midspan of AB. WD 3. For lateral bracing at supports only, what maximum w and w₁ can the beam carry for WL A WD = 26 kN/m_Includes self wt. WL = 40 kN/m B 10m ee m 2m PL16x380 PL12x500 X = 1.5.

7-12. The frame shown in the accompanying figure is unbraced against sidesway about the x-x axis. The columns are W8 and the beams are W12 x 16. ASTM AS72 steel is used for the columns and beams. The beams and columns are oriented so that bending is about ther-x axis Assume that K, = 1.0, and for column AB the service load is 175 k, in which 25 percent is dead load and 75 percent is live load. Select the lightest W8 shape for column AB. Moment connection. Typ. 13 ft 20 ft 20 ft 20 ft FIGURE P7-12

P.Pn Determine the LRFD design strength, P/2c for and the ASD allowable strength,' n' each of the compression members shown. Use the AISC Specification and a steel with F y = 50 ksi, except for Problem 5-8, Fy = 46 ksi. %3D (Ans. 212 k LRFD; 141 k ASD) W8 × 31 20 ft 0 in FIGURE P5-5