Civil Engineering Reference
In-Depth Information
2.7.5Example - checking a member under combined
tension and bending
Problem.
AtensionmemberconsistsoftwoequalanglesofS355steelwhoseends
are connected to gusset plates as shown in Figure 2.11c. If the load eccentricity
for the tension member is 39.1 mm and the tension and bending resistances are
1438 kN and 37.7 kNm, determine the resistance of the member by treating it as
a member under combined tension and bending.
Solution.
Substituting into equation 2.21 leads to
N
t
,
Ed
/
1438
+
N
t
,
Ed
×
(
39.1
/
1000
)/
37.7
≤
1
6.2.1(7)
so that
N
t
,
Ed
≤
577.2 kN.
Because the load eccentricity causes the member to bend about its minor axis,
there is no need to check for lateral buckling, which only occurs when there is
major axis bending.
2.7.6 Example 6 - estimating the stress concentration factor
Problem.
Estimate the maximum stress concentration factor for the tension
member of Section 2.7.1.
Solution.
For the inner line of holes, the net width is
b
net
=
60
+
30
−
22
=
68 mm,and so
r
/
b
net
=
(
22
/
2
)/
68
=
0.16,
and so using Figure 2.9, the stress concentration factor is approximately 2.5.
However, the actual maximum stress is likely to be greater than 2.5 times the
nominal average stress calculated from the effective area
A
net
=
161
×
10
2
mm
2
determined in Section 2.7.1, because the unconnected web is not completely
effective. Asafe estimate of the maximum stress can be determined on the basis
of the flange areas only of
A
net
=[
2
×
310.6
×
25
]−[
2
×
4
×
22
×
25
]+[
2
×
2
×
(
30
2
×
25
)/(
4
×
60
)
]
=
115.1
×
10
2
mm
2
.
2.8 Unworked examples
2.8.1 Example 7 - bolting arrangement
A channel section tension member has an overall depth of 381 mm, width of
101.6 mm, flange and web thicknesses of 16.3 and 10.4 mm, respectively, and an
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