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In members subjected to both axial load and bending, the presence of the primary moment produces secondary moments.

A W14x82 of A992 steel is to be investigated for use as a beam-column in an unbraced frame. The length is 14 feet. First-order analyses of the frame were performed for both the sway and nonsway cases. The factored loads and moments corresponding to one of the load combinations to be investigated are given for this member in the following table. The multiplier to account for P-δ effects was determined to be 1.05, and the multiplier to account for P-Δ effects was determined to be 1.30. Determine the required second-order axial strength, Pr, of the member.Type of analysisPu (kip)Mtop (kip-ft)Mbottom (kip-ft)Nonsway3355034Sway18045105 

An engineer analyzes an unbraced frame and determines the sum of the required load capacities for all the columns in the frame is 200 kips (unfactored) while the total elastic buckling strength of the same frame is 3,558 kips. From these values, what is the ASD amplification factor for sidesway moments of the frame?

Unbraced frames are frequently referred to as _______ frames.

Compute the value of Cm for a beam-column with a moment of 100 kip-ft at the top and a moment of 460 kip-ft at the bottom.

The beam-column of A992 steel is part of a braced frame with L = 15 ft, Pu = 280 kip, Mux = 130 kip-ft. A second-order analysis was performed with factored loads and reduced member stiffnesses to obtain the moments and axial force. Bending is about the strong axis. Considering only W14x68, W14x74, and W14x82, use ASD to select the lightest acceptable shape. Let Kx = 1.0, Ky = 1.0, and Cb = 1.0.

A W14x82 of A992 steel is to be investigated for use as a beam-column in an unbraced frame. The length is 14 feet. First-order analyses of the frame were performed for both the sway and nonsway cases. The factored loads and moments corresponding to one of the load combinations to be investigated are given for this member in the following table. The multiplier to account for P-δ effects was determined to be 1.20, and the multiplier to account for P-Δ effects was determined to be 1.25. Determine the required second-order axial strength, Pr, of the member.Type of analysisPu (kip)Mtop (kip-ft)Mbottom (kip-ft)Nonsway3704529Sway1804095 

The beam-column of A992 steel is part of a braced frame with L = 15 ft, Pu = 300 kip, Mux = 120 kip-ft. A second-order analysis was performed with factored loads and reduced member stiffnesses to obtain the moments and axial force. Bending is about the strong axis. Considering only the following shapes and values obtained from the AISC procedure for LRFD, select the lightest acceptable shape. Let Kx = 1.0, Ky = 1.0, and Cb = 1.0.ShapeValue of AISC interaction equationW12x580.941W12x720.688W12x790.624W12x870.561W12x960.505 

Compute the LRFD moment amplification factor B1 for the W12x106 made from ASTM A992 steel with L = 13 ft, P = 220 kip, M = 220 kip-ft, and Kx = Ky = 1.0. Bending is about the x axis. The member is part of a braced frame, and the given service loads are 40% dead load and 60% live load. The frame analysis was performed using the requirements for the approximate second-order analysis method meaning that a reduced stiffness was used.

A W14x82 of A992 steel is to be investigated for use as a beam-column in an unbraced frame. The length is 14 feet. First-order analyses of the frame were performed for both the sway and nonsway cases. The factored loads and moments corresponding to one of the load combinations to be investigated are given for this member in the following table. The multiplier to account for P-δ effects was determined to be 1.14, and the multiplier to account for P-Δ effects was determined to be 1.14. Determine the required second-order flexural strength, Mr, at the top of the member.Type of analysisPu (kips)Mtop (kip-ft)Mbottom (kip-ft)Nonsway4804532Sway19035105