Page 126 - Structural Steel Designers Handbook AISC, AASHTO, AISI, ASTM, and ASCE-07 Design Standards

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CONNECTIONS

3.58 CHAPTER THREE

3.5 AXIAL CONNECTIONS

Axial connections carry primarily tension or compression axial force, but may also involve shear and
moment as well.
3.5.1 Hanger Connections

The most interesting connection of the genre is the type that involves prying action, sometimes of
both the connection fitting and the supporting member. Figure 3.36 shows a typical example. The
calculations to determine the capacity of this connection are as follows. The connection can be bro-
ken into three main parts: the angles, the W16 × 57 piece, and the W18 × 50 supporting member. The
angles are A36 and the W sections are A992 steel. Bolts are A325N. The three main parts are joined
by two additional parts, the bolts of the angles to the piece W16 and the bolts from the piece W16
to the W18. The load path in this connection is unique. The load P passes from the angles through
the bolts into the piece W16, thence through bolts again into the supporting W18. The latter bolt
group is arranged to straddle the brace line of action. These bolts thus see only direct tension and
shear, and no additional tension due to moment. Statics is sufficient to establish this. Consider now
the determination of the design strength of this connection.

Angles. The limit states for the angles are gross tension, net tension, block shear rupture, and bear-
ing. The load can be compression as well as tension in this example. Compression will affect the
angle design, but tension will control the above limit states.

FIGURE 3.36 Typical bolted hanger connection. (Source: A. R. Tamboli, Handbook of Structural
Steel Connection Design and Details, McGraw-Hill, 1999, with permission.)

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