Civil Engineering Reference
In-Depth Information
Tension
55
(
6
)
10
(
4.0
)
=
Pe
10
y
=
T
=
8.3 kips
T
3
b
8.3
3
(
4.25
)
t
p
20
(
0.5
)
2
20
T
Q
=
8
a
−
=
8
(
1.5
)
−
=
8.7 kips
(
8.3
8.7
)
0.60
+
σ
bt
=
=
28.3 ksi
≤
f
bt
≤
44.0 ksi OK
Combined shear and tension
f
bv
1
17
1
(
8.3
+
8.7
)
(T)
(T
bP
)
≥ τ
bv
≥
f
bv
=
−
=
−
=
9.6 ksi
9.2 ksi OK
39
check bearing stress
σ
bc
=
55
10
(
0.50
)(
1.00
)
11.0 ksi, assuming that the minimum thickness of the
connection plate and the web is 0.5 in.
f
B
≤
=
l
e
F
u
2
d
b
(
1.5
)(
65
)
2
(
7
/
8
)
≤
≤
55.7 ksi, assuming that the minimum edge distance
is 1.5 in, OK
or
f
B
≤
1.2
F
u
≤
1.2
(
65
)
≤
78 ksi
9.3.4.3.2 Connections Subjected to Eccentric Shear Forces (Combined
Shear and Torsion)
A connection subjected to eccentric shear is shown in
Figure 9.20.
The bolts in the
connection resist direct shear forces from,
P
, and torsional shear forces from the
moment,
Pe
. The direct shear stress,
τ
, on the bolts (all bolts with the same
A
b
)
,is
P
n
s
A
b
=
P
n
s
n
b
A
b
τ =
(9.56)
and the torsional shear stress,
τ
T
, on the bolts is
Per
T
n
s
J
b
=
Per
T
n
s
n
b
A
b
r
T
Per
T
n
s
A
b
n
b
(x
T
+
y
T
)
.
τ
T
=
=
(9.57)
Equation 9.57 can be developed in the
x
- and
y
-directions as
Pey
T
n
s
A
b
n
b
(x
T
+
τ
T
x
=
y
T
)
,
(9.58a)
Pex
T
n
s
A
b
n
b
(x
T
+
τ
T
y
=
y
T
)
,
(9.58b)
where
n
b
is the total number of bolts in the connection;
n
s
is the number
of shear
planes;
J
b
= Σ
x
T
+
y
T
is the distance from the bolt to the centroid of the bolt group,
x
T
is the distance from
n
b
A
b
r
T
is the polar moment of inertia of connection;
r
T
=
