Application of Probability to Mechanical Design
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PROBLEMS
PROBLEM 2.1
A rectangular cross-section beam Fig. Prob. 2.1 is to be used to support a
chain hoist. Neglect the weight of the beam.
MC
SI
If I = bh 3 /12 and coefficients of variations are
CL = 4-2%; Cs = -t-10%; Cb = Ch = +1%
Find: (-~)with~’=10001bsandF.S.=l.25
PROBLEM 2.2
Assuming variations Cs = -t- 5.5% and Cp = 4- 5.% with F.S. = 1.25 in Problem 2.1 and Cb, and Ch are -t-1%.
Compute L. Compute the PU
PROBLEM 2.3
In designing spherical fuel tanks for a rocket engine, the internal diameters
are 10.00-t-0.05 in (P--0.99) and the specific weight of the fuel
50.0 -4- 0.6 lbm/cu.ft. (P = 0.99). Show which variable contributes the greatP
t
_j_
t =
L
Figure Problem 2.1