Civil Engineering Reference
In-Depth Information
Q
Q
Before
buckling
Q
After
buckling
-z
Q
-z
Q
n
L/
2
z
Q
f
L/
2
-
L/
2
L/
2
f
L/
2
(a) Elevation
(c) Section at mid-span
Q
(
v
-
z
Q
f
)
L/
2
2
x
Q/
2
d
v
v
v
L/
2
d
x
d
v
x
d
-
z
Q
f
L/
2
x
Q
(b) Plan on longitudinal axis
Figure 6.5
I-beam with a central concentrated load.
80
Approximate equation 6.4
with
m
=1.35
2
z
Q
/
d
f
=
1
Bottom flange
60
=
(
z
Q
/
L
)
(
EI
z
/
GI
t
)
=0.6
0
Centroid
40
0.3
0
-1
-0.3
20
-0.6
Top flange
0
0
0.5
1.0
1.5
2.0
2.5
3.0
Beam parameter
K =
(
2
EI
w
/
GI
t
L
2
)
√
Figure 6.6
Elastic buckling of beams with central concentrated loads.
For centroidal loading (
ε
=
0), the elastic buckling load
Q
increases with the
beam parameter
K
in much the same way as does the buckling moment of beams
Search WWH ::
Custom Search