Civil Engineering Reference
In-Depth Information
Therefore,
1.33
(
771.2
)
1.208
(
557.2
)
−
98.1
(
E80
)
=
LLT
=
1.39
(
E80
)
=
E111.
P
1
max
=+
54.56
+
1.208
(
+
332.4
)(
122
/
80
)
=
666.4 kips.
Strength considerations:
456.1
0.55
(
50
)
≥
16.6 in.
2
(tensile yielding)
A
g
≥
456.1
0.47
(
70
)
≥
13.9 in.
2
(fracture)
A
e
≥
due to strength-related shear lag effects at the connection (assuming
U
c
=
0.90)
13.9
U
c
≥
15.4 in.
2
(fracture)
A
e
≥
from the requirement related to live load LLT
611.7
1.33
(
0.55
)(
50
)
≥
16.7 in.
2
(tensile yielding)
A
g
≥
611.7
1.33
(
0.47
)(
70
)
≥
14.0 in.
2
(fracture)
A
e
≥
due to strength-related shear lag effects of LLT at the connection
14.0
U
c
=
15.6 in.
2
(fracture).
A
e
≥
Fatigue considerations:
A
efat
≥
(
385.7
/
16
)
≥
24.1 in.
2
for the gross area of connected elements of
the member
A
e
≥
(
385.7/24
)
≥
16.1 in.
2
for the net area of the member away from the
connection.
Stiffness considerations:
L
r
min
≤
200
(
27.25
)
2
+
(
19.55
)
2
(
12
)
r
min
≥
≥
2.01 in.
200
Select a member with the following section properties:
Minimum gross area of the member
18.2 in.
2
(tensile yielding)
Minimum gross area for portions of the member connected
=
A
g
≥
A
g
≥
=
24.1 in.
2
(fatigue)
Minimum net effective area of the member at the connection
=
A
e
≥
15.6 in.
2
(fracture)
Minimum net area of the member away from the connection
=
A
e
≥
16.1 in.
2
(fatigue)
Minimum radius of gyration
=
r
min
≥
2.01 in.
