Civil Engineering Reference
In-Depth Information
20. A framed structure is attached to a rigid table as shown in Figure 4.55. Use a finite
element analysis to compute the force
Q
needed to push point A down to the table
surface.
Ans:
Q
=
1348
.
5kN
Q
EI = 850 kNm
2
EA=10
6
kN
NOT TO SCALE
A
3
°
3
°
1m
1 m
Figure 4.55
21. A simply supported beam of length
L
and stiffness
EI
supports a uniformly dis-
tributed load
as shown in Fig-
ure 4.56. Use a single beam element to compute the end rotations, and hence estimate
the mid-point translation.
Ans:
q
and rests on an elastic foundation of stiffness
k
3
4
4
4
θ
=
+
w
mid
=
+
35
qL
/(
840
EI
7
kL
)
,
35
qL
/(
3360
EI
28
kL
)
EI, k
q
L
Figure 4.56
22. Compute the vertical deflection and rotation at the lower end of the system shown
in Figure 4.57. Use a single beam-rod element.
Ans:
U
1
=−
0
.
00112,
U
2
=
0
.
04792
0.5
Q= 100
EA=10
5
EI=10
2
50
°
1
Figure 4.57
