Page 113 - Handbook of Structural Steel Connection Design and Details

Design of Connections for Axial, Moment, and Shear Forces

98 Chapter Two

d. Top chord web crippling:

N t w 1.5 EF t f
yw
R 0.75 0.8 t 2 c1 1 3a ba b d
wcp w d t f B t w
70 0.510 1.5
2
5 0.75 3 0.8 3 .510 c1 1 3 a a b bd
14.3 0.855
29000s50ds0.855d
3 5 1890 kips . 119 kips, ok
B 0.510
In the web crippling check, the formula used is that for a location

greater than d/2 from the chord end because 13.5 70/2 48.5

in 14.31/2 7.2 in. is the position of the equivalent normal force.
Additionally, the restraint provided by the beam end connection is
sufficient to justify the check away from the end of the beam.
The checks for web yield and crippling could have been dismissed
by inspection in this case, but were completed to illustrate the
method. Another check that should be made when there is a couple
acting on a gusset edge is to ensure that the transverse shear
induced on the supporting member, in this case the top chord
W14 82, can be sustained. In this case, the induced transverse
shear is V 16.2 kips. The shear capacity of the W14 82 is
s
0.510 14.3 1.0 0.6 50 219 kips > 16.2 kips, ok. Now con-
sider for contrast, the couple of 15,860 kips-in shown in Fig. 2.21.
For this couple, V 15860/35 453 kips > 219 kips, so a 3/4 in.
s
doubler plate of GR50 steel is required as shown in Fig. 2.21.
2. Gusset to truss vertical:
a. Weld:

250
f 5 5.95 kips/in
v
2.21
87
f 5 2.07 kips/in
a
2 3 21
2
2
f 25.95 1 2.07 5 6.30 kips/in
R
6.30
Fillet weld size required 5 4.5 16 ths
1.392
Because of the flexibility of the end plate and truss vertical flange,
there is no need to size the weld to provide ductility. Therefore, use
a 5/16 fillet weld.
b. Bolts and end plate: The bolts are A325SC-B-X, 1
in standard
holes designed to the serviceability level, as is the default in the
specification. The end plate is 9 in wide and the gage of the bolts
1
is 5 / in. Thus, using the prying action formulation notation of the
2

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