Civil Engineering Reference
In-Depth Information
The section properties at the top and bottom weld are shown in
Tables E7.11 and E7.12, respectively. Shear flow at the weld, calculated based
on these section properties, is shown in Table E7.13.
TABLE E7.11
Top Weld of Flange-to-Web Connection
A
(in.
2
)
(in.
3
)
I
g
(in.
4
)
Ay
na
/
I
g
(in.
−1
)
Section
y
na
(in.)
Ay
na
9.79
×
10
−
3
Noncomposite (steel only)
50.00
43.75
2188
223,444
10.71
×
10
−
3
Composite—long term (
n
=
24)
37.50
40.16
1506
299,065
50.00
33.91
1696
11.31
×
10
−
3
Composite—short term (
n
=
8)
112.50
28.82
3242
386,516
50.00
22.57
1129
TABLE E7.12
Bottom Weld of Flange-to-Web Connection
A
(in.
2
)
(in.
3
)
I
n
(in.
4
)
Ay
na
/
I
n
(in.
−1
)
Section
y
na
(in.)
Ay
na
10.88
×
10
−
3
Noncomposite (steel only)
50.00
43.75
2188
201,100
9.70
×
10
−
3
Composite—long term (
n
=
24)
50.00
53.59
2680
276,408
8.94
×
10
−
3
Composite—short term (
n
=
8)
50.00
64.93
3247
363,234
Maximum shear flow
=
5.37 k/in.
3.51 k/in. (AREMA recommends that
even stress ranges in compression areas be considered due to the relatively
high “effective mean stress” caused by residual stresses)
Allowable weld shear stress
Maximum LL
+
I range shear flow
=
=
17.5 ksi (fillet)
Allowable fatigue stress range
=
16 ksi (fatigue detail Category B)
Weld size
=
5.37
/
[
2
(
0.71
)
17.5
]=
0.21 in.
0.16 in.
Use min 5
/
16
fillet welds or CJP welds (some designers will specify CJP
welds because of the vertical load on the top flange-to-web weld).
Weld size
=
3.52
/
[
2
(
0.71
)
16
]=
TABLE E7.13
Shear Flow at Flange-to-Web Connection
DL1 Shear
DL2 Shear
Maximum LL+I
Range of LL+I
Flow on
Flow on
Shear Flow
Shear Flow
Maximum
Location
Noncomposite
Composite
on Composite
on Composite
Shear
(Figure
Section
Section
Section
Section
Flow
E7.3)
(
n
=
1) (k/in.)
(
n
=
24) (k/in.)
(
n
=
8) (k/in.)
(
n
=
8) (k/in.)
(k/in.)
Top weld
0.69
0.43
4.25
3.51
5.37
Bottom weld
0.76
0.39
3.37
2.77
4.52
