Page 66 - Handbook of Structural Steel Connection Design and Details

Design of Connections for Axial, Moment, and Shear Forces

Design of Connections for Axial, Moment, and Shear Forces 51

which also must be done because the serviceability slip-critical con-
dition is used.
F nt
Fr 5 1.3F nt 2 f # F nt
nt
v
F nv
90 17.9
5 1.3 3 90 2 a b 5 69.6 ksi
0.75 3 48 0.994
Fr 5 0.75 3 69.6 5 52.2 ksi , 0.75 3 90 5 67.5 ksi , ok
nt
r 5 52.2 3 0.994 5 52.2 ksi . 27.4 kips, so bearing does
t
not control.
To determine the end plate thickness required, the critical dimen-
sion is the distance “b” from the face of the beam web to the
1
center of the bolts. For 5 / -in-cross centers, b (5.5 .5)/2 2.5 in.
2
To make the bolts above and below the flanges approximately
1
equally critical, they should be placed no more than 2 / in above and
2
below the flanges. Figure 2.2 shows them placed at 2 in. Let the
end plate be 11 in wide. Then a (11 5.5)/2 2.75 1.25 2.5
3.125 ok. The edge distance at the top and bottom of the end
plate is 1.5 in, which is more critical than 2.75 in, and will be used
in the following calculations. The notation for a and b follows that
of the AISC Manual as does the remainder of this procedure.
d 1.125
b b 2.5 1.9375
2 2
d 1.125
a a 1.5 2.0625
2 2
br
0.94
ar
1 rr t
5 a 2 1b
T
where T required tension per bolt 21.6 kips.

1 27.4
5 a 2 1b 5 0.286
0.94 21.6
1
r 5 mine a b, 1f
1 2

where 1 d /p 1 1.1875/4 0.70
In the above expression, p is the tributary length of end plate
per bolt. For the bolts adjacent to the beam web, this is obviously
4 in. For the bolts adjacent to the flanges, it is also approximately

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