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PROBLEM (10.145) In the fixed beam AB shown in Fig. P10.145, the left-hand support has settled
a distance δ0 below the right-hand support. Determine the support reactions.
SOLUTION
Consider RA and M A as redudants.
MA
δ0
A
L
RA
MA
RB
A
x
B
RA
M/EI
MB
B
L/2
MA/EI
A1
x
A2
-RAL/EI
2L/3
A1 =
θB/ A
M AL
1 RA L2
A2 = −
2 EI
EI
0
0
= θ B − θ A = A1 + A2
Thus,
2 M A = RA L
(1)
2
3
M L R L
2
L
t A / B = −δ 0 = A1 ( ) + A2 ( L) = A − A
2
3
2 EI
3EI
or
6 EI δ 0
−2 RA L + 3M A = −
L2
From Eqs. (1) and (2):
12 EI δ 0
↓
RA = −
L3
MA = −
(2)
6 EI δ 0
L2
Continued on next slide
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Symmetry dictates that
RB = − RA ↑
MB = MA
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