Civil Engineering Reference
In-Depth Information
For
a
CJP weld with backing bar removed, the weld size must be
≥
0.5
√
2
(
3.37
)/
16
0.15 in. OK since the web thickness is 0.625 in.
In general, CJP weld design does not need to be considered.
≥
Design of Web Plate Stiffeners:
Use angles bolted to the web in order to preclude fatigue issues related
to welding at the base of the transverse stiffeners.
The spacing of the stiffeners is
a
0
< h
=
85 in.
<
96 in.
1.95
t
w
E
τ
1.95
(
0.625
)
29,000
< a
≤
≤
486/53.13
≤
68.6 in.
Use a stiffener spacing of
(
11.25
)(
12
)/
2
=
67.5 in. (1/2 the distance between
brace frames)
h
a
0.7
2.5
(
67.5
)(
0.625
)
3
85
68.6
0.7
2
2
2.5
a
0
t
w
34.4 in.
4
.
I
ts
=
−
=
−
=
1
As shown in
Figure E7.2a,
a single 6
×
4
×
2
angle on one side of the web plate
4.75
(
1.99
)
2
36.2 in.
4
.
provides
I
ts
=
17.4
+
=
Design of Bearing Stiffeners
:
As shown in Figure E7.2b, the bearing stiffeners are to consist of 4
−
L
8
×
1
4
×
2
.
30.50 in.
2
,
A
ebs
=
2
A
bs
+
A
wbs
=
2
A
bs
+
12
t
w
=
2
(
2
)(
5.75
)
+
12
(
0.625
)
=
2
A
bs
y
2
t
w
=
2
(
2
)(
5.75
)(
3.17
)
2
+
(
0.625
)
4
I
ebs
=
2
I
bs
+
+
2
(
2
)(
38.5
)
+
385.6 in.
4
,
=
385.6
30.50
=
r
ebs
=
3.56 in.,
h
r
ebs
=
85
3.56
=
23.9,
0.839
E
/
F
y
=
20.2 and, therefore, the governing expression for allowable
compressive stress is Equation 7.74
17,500
F
y
E
3
/
2
0.75
h
r
ebs
F
call
=
0.60
F
y
−
=
30
−
0.124
(
17.9
)
=
27.8 ksi,
P
call
=
(
27.8
)(
30.50
)
=
847 kips
>
486 kips OK.
The reduced bearing stiffener area assuming a 1/2
clip is made to clear
the fillet at the web-to-flange junction (from double bevel CJP groove welds),
A
bs
=
15.0 in.
2
.
2
(
2
)(
8
−
0.50
)(
0.5
)
=
A
bs
(
0.83
F
y
)
≤
(
15.0
)(
0.83
)(
50
)
≤
R
=
486
≤
622.5 kips OK
