Example

Using ASD, determine the amount of increase in flexural capacity of a W24 x 55 section bent about its major axis if two 7 in. x 2 in. (178 mm x 13 mm) cover plates are bolted to its flanges as shown in Figure 4.9. The beam is laterally supported at every 5-ft (1.52-m) interval. Use A36 steel. Specify the type, diameter, and longitudinal spacing of the bolts used if the maximum shear to be resisted by the cross-section is 100 kip (445 kN).

FIGURE 4.9 Beam section with cover plates.

Section properties: A W24 x 55 section has the following section properties:

bf = 7.005 in., tf = 0.505 in., d = 23.57 in., tw = 0.395 in., Ix = 1350 in.4, Sx = 114 in.3

Check compactness: Refer to Table 4.8, and assuming that the transverse distance between the two bolt lines is 4 in., we have

Beam flanges

Beam web

Cover plates bf

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