Timothy A. Philpot - Mechanics of materials _ an integrated learning system-John Wiley (2017)

p8.54 The bracket shown in Figure P8.54 is subjected to a load
P = 1,300 lb. The bracket has a rectangular cross section with a
width b = 3.00 in. and a thickness t = 0.375 in. If the tensile normal
stress must be limited to 24,000 psi at section a–a, what is the maximum
offset distance y that can be used?
p8.56 The U-shaped aluminum bar shown in Figure P8.56 is
used as a dynamometer to determine the magnitude of the applied
load P. The aluminum [E = 70 GPa] bar has a square cross section
with dimensions a = 30 mm and b = 65 mm. The strain on the inner
surface of the bar was measured and found to be 955 mε. What is the
magnitude of the load P?
P
b
y
a
t
P
b
P
a
Strain gage
FIGURE p8.56
a
FIGURE p8.54
p8.55 A wall-mounted jib crane is shown in Figure P8.55a. The
overall dimensions of the crane are a = 102 in., b = 52 in., c = 66 in.,
and e = 5.0 in. The cross-sectional dimensions of the crane rail
(Figure P8.55b) are b f = 4.0 in., t f = 0.5 in., d = 6.0 in., and t w =
0.3 in. Assume that a hoist load P = 2,000 lb is located as shown
in Figure P8.55a. What is the maximum normal stress in the
crane rail?
p8.57 The steel pipe shown in Figure P8.57 has an outside
diameter of 195 mm, a wall thickness of 10 mm, an elastic modulus
E = 200 GPa, and a coefficient of thermal expansion α =
11.7 × 10 −6 /°C. Using a = 300 mm, b = 900 mm, and θ = 70°,
calculate the normal strains at H and K after a load P = 40 kN
has been applied and the temperature of the pipe has been
increased by 25°C.
C
a
y
(1)
c
θ
A
x
a
Crane rail
b
D
B
e
b
P
H
K
P
FIGURE p8.55a
b f
FIGURE p8.57
t f
y
z
t w
FIGURE p8.55b
d
p8.58 A short length of a rolled-steel [E = 29 × 10 3 ksi] column
supports a rigid plate on which two loads P and Q are applied as
shown in Figure P8.58a/59a. The column cross section (Figure
P8.58b/59b) has a depth d = 8.0 in., an area A = 5.40 in. 2 , and a
moment of inertia I z = 57.5 in. 4 . Normal strains are measured with
strain gages H and K, which are attached on the centerline of the
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