sm12 47

________________________________________________________________________
PROBLEM (12.47) A cantilever beam is loaded as shown in Fig. P12.46. Apply Castigliano’s
theorem to determine the deflection of the free end.
B
v
SOLUTION
A
C
P
a
x
B
Q
b
L
x
Segment BC
M
11 Qx M Q x=− ∂ ∂ =−
Segment AC
2
2(), M
M
Qx P x b x
Q
∂
=− − − =−
∂
So,
BMM
vd
EI Q
∂
=∂
∫x
Let Q=0:
1()()
L
Bb
vPxb
EI
=−−−
∫xdx
33 22
11
[( ) ( )
32
Pb
PL b L b
EI
=−−−
]
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