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The beam-column of A992 steel is part of a braced frame with L = 15 ft, Pu = 320 kip, Mux = 105 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.

Compute the LRFD moment amplification factor B1 for the W8x58 made from ASTM A992 steel with L = 15 ft, P = 300 kip, M = 270 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 consistent with the effective length method, so the flexural rigidity was unreduced.

Which of the following corresponds to the variable B2?

Which of the following corresponds to the variable B1?

Compute the value of Cm for a beam-column in single-curvature bending with a moment of 150 kip-ft on one end and a moment of 600 kip-ft on the other end.

Compute the value of Cm for a beam-column with a moment of 510 kip-ft at the top and a moment of 120 kip-ft at the bottom.

An unbraced rigid frame depends on the transfer of moments at its joints for stability. For this reason, unbraced frames are frequently referred to as _______ frames.

Using LRFD, determine the value of the AISC interaction equation for a W8x58 made from ASTM A992. Let L = 16 ft, Kx = Ky = 1.0, and Cb = 1.0. The factored loads are Pnt = 281.2 kip, Mnt = 177.6 kip-ft, The member is part of a braced frame, bending is about the x axis, and the LRFD moment amplification factor has been determined to be B1 = 1.248.

Compute the LRFD elastic critical buckling strength, Pe1, for the W18x65 made from ASTM A992 steel with L = 16 ft, P = 200 kip, M = 200 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 50% dead load and 50% live load. The frame analysis was performed consistent with the effective length method, so the flexural rigidity was unreduced.

In the AISC 360 equation Mr = B1Mnt + B2Mlt, the variable B2 is the amplification factor for the moments resulting from sidesway.