structure analysis i. lecture 13 cables & arches ch.5 in text book
TRANSCRIPT
Cables
• Cables are often used in engineering structure to support and or transmit loads from one member to another
kNT
TT
M
CD
CDCD
A
79.6
0)4(8)2(35.52
0
54
53
oBC
BC
BCBCy
BCBCx
T
TF
TF
3.32
82.4
0sin8)(79.60
0cos)(79.60
54
53
0
0
2
L
R
R
y
x
L
wLR R F
H H H F
_
2
0 02 2
V=0
0 02 2
2
0
4
8
mid span x
y
wL L wL LH f M
wLH
wL
f
H
wLV F
H F
Analysis Procedure
_
2
2
2
0
0
02
8
4
2 2
.2
.2
2
02
V= 2
0mi s an x
y
d p
wL x wxH y M
w
wLH
ff x
wLwx
LH y wx x
wxH
V F
wLwx
y L x
w xy L x
y
H
L
F
x
H
H
L
@ 0
0 2 2.
0 0
V
=
0
L
L
R x
L
L
L y
L
M B
wL xR x H y
H y R wx x
R wx xH
y
R wx V F
R
H
wx
H F
General Case
2
2 2
2 2
42.4220 425 36459.2 36.46
2 425(41.42) 17.6
425(100) 17600 24900 24.9
36.46 24.
,
9 61.7
36.46 17.6
1
1
50.
0
0
7
0 0
Cy right part
y al A
A
A
C
Al
also from f
from f
V W
H I
x
V
b k
k
V Ib k
T k
T
from
W V
k
x100 x
2 2 2 2max
500 307500 Ib=7.5k
2 2
7.031 7.5 10.280
A B
A B
WLV V
T T T H V
Example 3Determine the tension of the cable at points A, B
2500 30
7031.258 8
H
2
8
wLH
f
HH
AVBV
Example 1Determine the internal forces at Section D
kNA
kNA
F
kNB
BM
kNB
BM
y
x
x
x
xRightC
y
yA
93
0F
86
0
86
0)20(67)8(60)6(0
67
0)28(60)10(100)40( 0
y
22
2
12
25
25
5025
250
25tan 2 25 0.5
50
26.6
x
o
y x
dyx
dxdy
dx
25cos 12.5sin 27.95
25 12.5cos 11.18
25(6.25) 12.5(12.5) 0
D
D
D
N
V sin
M
26.6o