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sm10 112 113

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PROBLEMS (10. 112 and 10.113) A cantilever beam supports a partial uniform load of intensity
w as shown in Figs. P10.112 and P10.113. Determine:
(a) The angle of rotation at free end B.
(b) The deflection at the free end B.
SOLUTION (10.112)
w
B
A
EI
L/2
3EI
L/2
M
x
−3wL2 8
x1
M
EI
− wL2 8EI
− wL2 24 EI
A1
A2
x
A3
− 8wLEI
2
Parabolic
Spandrel
x3
x2
Tangent at A
A
vB
B
1 wL2 L
wL3
=−
2 24 EI 2
96 EI
2
1 wL L
wL3
A2 = −
=−
2 8EI 2
32 EI
2
1 wL L
wL3
A3 = −
=−
3 8EI 2
48EI
A1 = −
θB
L L 2L
+ =
2 6
3
L L 5L
x2 = + =
2 3 6
3 L 3L
x3 = ( ) =
4 2
8
x1 =
(a) θ B / A = θ B − θ A0 = A1 + A2 + A3
θB = −
wL3
wL3
(1 + 3 + 2) =
96 EI
16 EI
Continued on next slide
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(b) t B / A = vB
=−
wL3 2 L wL3 5L wL3 3L
−
−
96 EI 3 32 EI 6 48EI 8
or
vB = −
wL4
47 wL4
(8 + 30 + 9) =
↓
1152 EI
1152 EI
SOLUTION (10.113)
w
a
A
a
C
M
EI
x2
x1
− wa 2 2 EI A2
−3 wa 2 2 EI
B
a
D
A3
x
Spandrel
Parabolic
A1
x3
Tangent at A
vB
A
D
B
θB
bh
1 wa 2
wa 3
A1 =
=− a
=−
3EI
3 2 EI
6 EI
3
wa
1
1 wa 3
A2 = −
A3 = − a( wa 2 ) = −
2 EI
2
2 EI
x1 = a +
3a 7 a
=
4
4
x2 =
5a
2
x3 =
8a
3
(a) θ B / A = θ B − θ A0 = A1 + A2 + A3
θB = −
wa 3
7 wa 3
(2 + 6 + 6) =
12 EI
6 EI
Continued on next slide
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instructional purposes only to students enrolled in courses for which the textbook has been adopted. Any other
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(b) t B / A = vB = A1 x1 + A2 x2 + A3 x3
vB = −
wa 4
69 wa 4 23 wa 4
(7 + 30 + 32) = −
=
↓
24 EI
24 EI
8 EI
Excerpts from this work may be reproduced by instructors for distribution on a not-for-profit basis for testing or
instructional purposes only to students enrolled in courses for which the textbook has been adopted. Any other
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