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TRUSSES SAMPLE QUESTIONS. 4 m. 4 m. 4 m. E. D. 4 m. r=400 mm. H. G. C. F. 4 m. B. 16 kN. 4 m. A. - PowerPoint PPT Presentation
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TRUSSES
SAMPLE QUESTIONS
4 m
4 m
4 m 4 m
4 m
4 m
r=400 mm
16 kN
A
C
D
B
E
F
GH
1. The crane in the figure consists of a planar truss. Determine the forces in members
DE, DG and HG when the crane supports a 16 kN load, indicate whether the members
work in tension (T) or compression (C).
2. Determine the forces in members BC and FG.
CutFBC
FCJ FFJ
FG
3. Determine the forces in members CD, CJ and DJ, state whether they work
in tension (T) or compression (C).
Ax
Ay
T
I. Cut
3 m
FCD
FDJ
FJI
Ax
Ay
T
II. Cut
FCD
FCJ
FKJ
4. The truss shown consists of 45° triangles. The cross members in the two
center panels that do not touch each other are slender bars which are incapable
of carrying compressive loads. Identify the two tension members in these panels
and determine the forces they support. Also determine the force in member MN.
Ax
AyBy
I. Cut
II. Cut
5. Determine the force acting in member DK.
Ux
Uy
Vy
Uy=15 kNVy=20 kN
II. Cut I. CutIII. Cut
IV. Cut
6. Determine the forces in members DE, EI, FI and HI.
4/47
Gx
Ay
I. Cut
Gy
II. Cut
7. Determine the forces in members ME, NE and QG.
I. Cut III. CutII. Cut
20 kN
2 m
2 m
2 m
4 m3 m 3 m 4 m4 m4 m
A
B C D
E F
G
N
M
L K
J
H
P
10 kN6 kN
Radii of pulleys H, F and K 400 mm
4 kN
8. In the truss system shown determine the forces in members EK, LF, FK and CN,
state whether they work in tension (T) or compression (C). Crossed members do not
touch each other and are slender bars that can only support tensile loads.
2 m
2 m
2 m
4 m3 m 3 m 4 m4 m4 m
A
B C D
E F
G
N
M
L K
J
H
P
10 kN6 kN
20 kN
4 kN
10 kN10 kN
10 kN
10 kN
10 kN
Ax
By
Bx
(I) (II)
(III)
(IV)
Radii of pulleys H, F and K 400 mm
9. Determine the forces in members EF, NK and LK.
C
B
A
D E F G
HO
L K JI
N
1 kN
2 kN 2 kN2 kN 5 kN
2 kN 2 kN2 kN
4 m
4 m
3 m 3 m 3 m 3 m
M
3
4
From the equilibrium of whole truss
Ax, Ay and Iy are determined
I. Cut
MH=0
FAB is determined
C
B
A
D E F G
HO
L K JI
N
1 kN
2 kN 2 kN2 kN 3 kN
4 kN
2 kN 2 kN2 kN
4 m
4 m
3 m 3 m 3 m 3 m
I. Cut
Top Part
Ay Iy
M
Ax
FHI
FHOFMOFMNFBN
FBA
II. Cut
MM=0
FEF and FMF are determined
C
B
A
D E F G
HO
L K JI
N
1 kN
2 kN 2 kN2 kN 3 kN
4 kN
2 kN 2 kN2 kN
4 m
4 m
3 m 3 m 3 m 3 m
II. Cut
Top Part
M
FEF
FMF
FMOFMNFBN
FBA
III. Cut
MN=0
FLK and FNK are determined
C
B
A
D E F G
HO
L K JI
N
1 kN
2 kN 2 kN2 kN 3 kN
4 kN
2 kN 2 kN2 kN
4 m
4 m
3 m 3 m 3 m 3 m
III. Cut
Left Side
MFMO
FLK
FNK
FMF
FEF
10. Determine the forces in members KN, FC and CB.
kN
kN
kN
kN
kN
1 m
1 m
1 m
2 m
2 m1 m1 m2 m
A B
C D
O
E
G
P F
NM
I
JK
L
H
225
225
220
210 210
Forces in KN, FC and CB.
kN
kN
kN
kN
kN
1 m
1 m
1 m
2 m
2 m1 m1 m2 m
A B
C D
O
E
G
P F
NM
I
JK
L
H
225
225
220
210 210
I. Cut
II. Cut
III. Cut
IV. Cut
ByAy
Ax