Page 145 - Handbook of Structural Steel Connection Design and Details

Design of Connections for Axial, Moment, and Shear Forces

130 Chapter Two

1
1
1
welds for the / 6 / 12 / strong axis stiffener are designed as fol-
2 2 2
lows. For the weld to the inside of the flange, the force to be developed
3
by the weld to the connected portion is 29 kips. Thus, the 5 / contact,
4
which is the connected portion, is designed for 29 kips. The weld to the
flange is thus
29
D 5 5 1.21
f
2 3 5.75 3 1.392 3 1.5
An AISC minimum fillet weld is indicated. The factor 1.5 in the
denominator above comes from the AISC Specification, Section J2.4,
for transversely loaded fillets. The weld to the web has a length 12.5
0.75 0.75 11.0, and is designed to transfer the unbalanced force in
the stiffener to the web. The unbalanced force in the stiffener is 29 kips
in this case. Since the weld at the web and the weld at the flange do not
share load in this case, both the longitudinally and transversely loaded
welds can develop their full strength. Thus,

29
D 5 5 0.95
w
2 3 11.0 3 1.392
An AISC minimum fillet is indicated.

2.3.2.1 Doublers. The beam flange force (required strength) delivered
to the column is F 229 kips. The design shear strength of the column
f
V 0.9 0.6 50 0.485 14.16 185 kips 229 kips, so a doubler
v
appears to be required. However, if the moment that is causing doublers
is M 389 kips-ft, then from Fig. 2.34, the column story shear is
b
M b
5
V s
H
where H is the story height. If H 13 ft,

389
V s 5 5 30 kips
13
and the shear delivered to the column web is F V 229 30 199
f s
kips. Since 199 kips > 185 kips, a doubler (or doublers) is still indicated.
If some panel zone deformation is acceptable, the AISC Specification
Section J10.6, Formula J10-11 or J10-12, contains an extra term which
increases the panel zone strength. The term is

2 2
3b fc t fc 3 3 14.6 3 0.780
5 5 0.184
d b d c t wc 21.0 3 14.2 3 0.485

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