Frame 3. The third frame evaluated is a two-bay, one-story plane frame with unequal bay widths and story heights. The larger bay was 36 ft wide and 36 ft high. It was subjected to a
9 12 k/ft gravity load acting on the beam and a 40 k lateral load acting on the upper left node. The smaller bay frames into the right column of the larger bay and is 24 ft wide and 24 ft high. A 16 k/ft gravity load was applied to the beam and an 18k lateral load was applied to the upper right node of the bay. The frame configuration and loading are shown below in Figure 3.3. Figure 3.3: Geometry, Loading and Member Sizes for Frame 3 Based on a first-order analysis, W18x143 sections were chosen for the exterior columns, a W18x158 section was chosen for the interior column, a W30x211 section was chosen for the beam of the larger bay, and a W33x130 section was chosen for the beam of the smaller bay, as shown in Figure 3.3. Frame 4. The fourth frame analyzed is a gabled plane frame, measuring 80 ft wide and 25 ft high, with roof beams sloped at 4.7 degrees from the horizontal, resulting in a total height of 28.3 ft. The ends of both columns are pinned connections. A live load of 0.5 k/ft was applied to the beams globally, in the gravity direction. A dead load of 0.25 k/ft was applied to the beams locally, acting normal to the beams. Additionally, a 9.4 k wind load was applied to the upper left node of the frame, at the top of the column and a 2.5 k wind load was applied to the hip of the roof. The loads were combined and factored according to LRFD specifications with the resulting loads shown in Figure 3.4. A first-order analysis was performed on the frame and as a result, the columns are W18x143 sections and the beams are W10x49 sections, as shown in Figure 3.4.
10 Figure 3.4: Geometry, Loading and Member Sizes for Frame 4 Frame 4a. Frame 4a, has the same geometry as Frame 4, except that the roof pitch is 18.4 degrees from the horizontal, resulting in a total structure height of 38.3 ft. The same loads were applied to the structure, except that the increase in height resulted in an increased wind load of 10.1 k at the tip of the gable, as shown in Figure 3.5. A first-order analysis was performed and the previously sized members proved adequate for the increased loading. Figure 3.5: Geometry, Loading and Member Sizes for Frame 4a Frame 5. The sixth frame considered is a four-bay, one-story plane frame. The frame is 25 ft tall and each bay is 40 ft wide, with a total width of 160 ft. Each of the column bases is
11 pin-connected and the exterior beam-to-column connections are full moment connections, while the interior beam-to-column connections are simple shear connections, so that the interior columns are “leaner” columns. A live load of 0.5 k/ft and a dead load of 0.25 k/ft were applied to the beams and a 9.4 k wind load was applied to the upper left node of the structure. The loads were combined and factored according to LRFD specifications with the resulting loads shown in Figure 3.6.
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