Page 65 - Handbook of Structural Steel Connection Design and Details

Design of Connections for Axial, Moment, and Shear Forces

50 Chapter Two

which is reasonable. Note that this length can be longer than the
gusset-to-beam weld, but probably should not exceed about half the
beam span.
The vertical component can cause beam web yielding and crippling.
(1) Web yielding: The web yield design strength is

R 1 0.51 50(51.25 2.5 1.45) 1400 kips >168 kips, ok
wy
(2) Web crippling: The web crippling design strength is
N t w 1.5 EF t
y f
2
R wcp 5 0.75 3 0.8 3 t w c1 1 3a ba b d
d t f B t w
51.25 0.51 1.5
2
5 0.75 3 0.8 3 0.510 c1 1 3a ba b d
14.3 0.855
29,000 3 50 3 0.855
3 5 1450 kips . 168 kips, ok
B 0.51
The above two checks on the beam web seldom control but should
be checked “just in case.” The web crippling formula used is that
for locations not near the beam end because the beam-to-column
connection will effectively prevent crippling near the beam end.
The physical situation is closer to that at some distance from the
beam end rather than that at the beam end.
4. Beam to column: The loads are 216 kips axial, the specified transfer
force and a shear which is the sum of the nominal minimum beam
shear of 10 kips and the vertical force from the gusset-to-beam con-
nection of 168 kips. Thus, the total shear is 10 168 178 kips.
a. Bolts and end plate: As established earlier in this example, the bolt
design strength in shear is r 31.6 kips. In this connection,
str
since the bolts also see a tensile load, there is an interaction
between tension and shear that must be satisfied. If V is the fac-
tored shear per bolt, the design tensile strength is
V
r 5 1.13T a1 2 b # 0.75 3 90A b
t
b
r str
This formula is obtained by inverting Specification formula J3-5a.
1
T is the bolt pretension of 56 kips for A325 1 / -in-diameter bolts
b 8
2
2
and A is the bolt nominal area /4 3 1.125 5 0.994 in .
b
For V 179/10 17.9 kips 31.6 kips, ok,
r 5 1.13 3 56s1 2 17.9/31.6d 5 27.4 kips and 0.75 90 .994
t
67.1 kips.
Thus rr 5 27.4 kips and R 10 27.4 274 kips > 216 kips,
t
t
ok. Checking the interaction for an N-type bearing connection,
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