05-01ChapGere.0009 - A-PDF Split DEMO Purchase from...

Solution 5.5-9 Beam in an oil-well pump
SECTION 5.5 Normal Stresses in Beams
293
L 14 ft
P 8.8 k
b 8.0 in. h 20.0 in.
t
f
0.875 in. t
w
0.625 in.
h
1
h 2 t
f
18.25 in.
b
1
b t
w
7.375 in.
M
max
PL (8.8 k)(14 ft)
123,200 lb-ft 1,478,400 lb-in.
5,333.3 in. 4 3,735.7 in. 4 1,597.7 in. 4
9250 psi 9.25 ksi
s
max
M
max
c
I
(1.4784 10
6
lb-in.)(10.0 in.)
1,597.7 in.
4
1
12
(8.0 in.)(20.0 in.)
3
1
12
(7.375 in.)(18.25 in.)
3
I
bh
3
12
b
1
h
1
3
12
s
max
M
max
c
I
c
h
2
10.0 in.
b
t
f
h
1
h
2
t
w
L
P
Problem 5.5-10 A railroad tie (or sleeper ) is subjected to two rail
loads, each of magnitude P 175 kN, acting as shown in the figure.
The reaction q of the ballast is assumed to be uniformly distributed
over the length of the tie, which has cross-sectional dimensions
b 300 mm and h 250 mm.
Calculate the maximum bending stress
max
in the tie due to