Civil Engineering Reference
In-Depth Information
Ans
.
W
0
.
3
M
. Horizontal: 0.44
W
at A, 0.56
W
at G. Vertical: 0.89
W
at A,
2.11
W
at G.
=
W
W
W
W
B
C
D
E
F
2
M
M
6m
9m
2
m
G
A
3m
3m
3m
3m
F
IGURE
P.18.11
P.18.12
The steel frame shown in Fig. P.18.12 collapses under the loading shown.
Calculate the value of the plastic moment parameter
M
if the relative plastic moments
of resistance of the members are as shown. Calculate also the support reactions at
collapse.
Ans
.
M
56 kNm. Vertical: 32 kN at A, 48 kN at D. Horizontal: 13.3 kN at A,
33.3 kN at D.
=
40 kN
40 kN
20 kN
B
E
F
C
2
M
6m
M
M
A
D
3m
3m
3m
3m
3m
F
IGURE
P.18.12
P.18.13
The pitched roof portal frame shown in Fig. P.18.13 has columns with a plastic
moment of resistance equal to
M
and rafters which have a plastic moment of resistance
equal to 1.3
M
. Calculate the smallest value of
M
that can be used so that the frame
will not collapse under the given loading.
Ans. M
=
24 kNm.
