Civil Engineering Reference
In-Depth Information
w
A
B
L
F
IGURE
P.15.4
P.15.5
Calculate the forces in the members FG, GD and CD of the truss shown in
Fig. P.15.5 using the principle of virtual work. All horizontal and vertical members are
1m long.
Ans.
FG
=+
=+
=−
20 kN GD
28
.
3kN CD
20 kN.
E
F
G
10 kN
A
D
B
C
20 kN
F
IGURE
P.15.5
P.15.6
Use the unit load method to calculate the vertical displacements at the quarter-
and mid-span points in the beam shown in Fig. P.15.6.
Ans.
57
wL
4
/
6144
EI
5
wL
4
/
384
EI
. (both downwards)
w
A
B
EI
L
F
IGURE
P.15.6
P.15.7
Calculate the deflection of the free end C of the cantilever beam ABC shown
in Fig. P.15.7 using the unit load method.
Ans. wa
3
(4
L
−
a
)
/
24
EI
.
(downwards)
