Chapter 1

Problems 1-1 through 1-6 are for student research. No standard solutions are provided.

1-7 From Fig. 1-2, cost of grinding to 0.0005 in is 270%. Cost of turning to 0.003 in is

60%. Relative cost of grinding vs. turning = 270/60 = 4.5 times Ans.

______________________________________________________________________________ 1-8 CA = CB, 10 + 0.8 P = 60 + 0.8 P 0.005 P 2

P = 100 parts Ans. P 2 = 50/0.005

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1-9 Max. load = 1.10 P Min. area = (0.95)2A Min. strength = 0.85 S To offset the absolute uncertainties, the design factor, from Eq. (1-1) should be

1.10

nd 1.43Ans. 2

0.85 0.95 ______________________________________________________________________________

1-10 (a) X1 + X2:

x1 x2 X1 e1 X2 e2

error e x1 x2 X1 X2

e1 e2 Ans.

(b) X1 X2:

x1 x2 X1 e1 X2 e2 e x1 x2 X1 X2 e1 e2 Ans.

x1x2 X1 e1 X2 e2

e x1x2 X1X2 X1e2 X2e1 e1e2

(c) X1 X2:

ee

X1e2 X2e1 X1X2 1 2 Ans.

X1X2