Civil Engineering Reference
In-Depth Information
Q
D
= 60 kN
Q
I
= 100 kN
at top flange
3.75 m
3.75 m
(a) Example 1
Quantity
610×229 UB 125 457×191 UB 82
Units
b
f
229.0
191.3
mm
t
f
19.6
16.0
mm
h
612.2
460.0
mm
t
w
11.9
9.9
mm
r
12.7
10.2
mm
W
pl,y
3676
1831
cm
3
cm
4
I
z
3932
1871
cm
4
I
t
154
69.2
dm
6
I
w
3.45
0.922
(b) Section properties
Figure 6.30
Examples 1 and 4.
Section resistance.
As in Section 5.12.15,
f
y
=
265 N/mm
2
, the section is Class 1, and the section
resistance is
M
c
,
Rd
=
974kNm
>
433kNm
=
M
Ed
and the section resistance is
adequate.
Elastic buckling moment.
Using equation 6.56 to allow for the partial torsional end restraints
k
cr
=
1
+{
(
612.2
−
19.6
)/(
6
×
7500
)
}
(
19.6
/
11.9
)
3
×{
1
+
229.0
/(
612.2
−
19.6
)
}
/
2
=
1.041
so that
L
cr
=
1.041
×
7500
=
7806mm.
Adapting equation 6.36,
π
2
×
210000
×
3932
×
10
4
7806
2
M
zx0
=
81000
×
154
×
10
4
+
π
2
×
210000
×
3.45
×
10
12
7806
2
×
Nmm
=
569 kNm.
Using equation 6.12,
N
cr
,
z
=
π
.2
×
210000
×
3932
×
10
4
/
7500
2
N
=
1449kN.
Search WWH ::
Custom Search