T

4 0.6Fy

Alternatively, when applied to the effective net area, T

0.5Fu

Ag is the gross area of the section and Ae is the effective net area, both as defined in the AISC. If end connections are welded and the area not otherwise reduced, Ag = Ae. For bolted members, determination of the reduced cross-section area An is required by searching for different possible chains of holes. When a chain of holes is straight and perpendicular to the member axis,

An = Ag - fNt where f = effective diameter of the hold = fb + | in.: (fb is the bolt diameter) N = number of bolts in the chain t = thickness of material being connected

Although the slenderness ratio l/r for tension members is not critical, AISC recommends a nonmandatory limit of l/r < 300. Flexible members such as cables, round or square rods, or thin wide bars are excluded from this requirement.

7.1.1.1. Design Examples

7.1.1.1.1. Plates in Tension, Bolted Connections.

Given. A bolted joint connecting two 12"-wide x 3/4"-thick plates with 1" f bolts in standard holes. See Fig. 7.1a. The plate material is Fy = 50 ksi and Fu = 65 ksi. Assume block shear does not govern and that the bolts are satisfactory.

Figure 7.1. Bolted plate in tension: (a) elevation; (b) section; (c) welded plate in tension; design example.

Figure 7.1. Bolted plate in tension: (a) elevation; (b) section; (c) welded plate in tension; design example.

Required. Calculate the tensile force that can be applied to the plates. Solution.

Diameter of hole dh = 1 + 1/8 = 1.125 in. Gross area of plate Ag = 12 x 0.75 = 9 in.2 0.85Ag = A, (max) = 0.85 x 9 = 7.65 in.2 For fracture line A-A, see Fig. 7.1a; the effective net area of the plate is

A, = t (w - 2dh) = 0.75 (12 - 2 x 1.125) = 7.31 in.2

The tensile capacity for this fracture condition along line A-A is

For the staggered fracture line B-B, the effective net area of the plate is f m \

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