Question

WCA(worst case analysis) RSS(root sum of squares)

1. A cylindrical hole is bored through a steel block, and a cylindrical piston is machined to fit into the hole. The diameter of the hole is 20.00 ±0.01 cm, and the diameter of the piston is 19.90 0.02 cm. The clearance is one-half the difference between the diameters, 0.05. (a) Using WCA, determine if the piston assembly will meet the specified clearance of 0.04 (b) Using RSS, determine the probability that the clearance will be less than 0.04 cm. cm.

Answer 1

Alternative method of calculations of wca with a loop diagram:

model toleanenq case Ansnbist in-the loop n= number of. dnrensfong ominal dPmensToné factor t - tolerance fpread 19.9 20 O he mean ap tor the requfrcment 1 maxfmum expected vaYatron da , ce (2-)-o IS 20-14 o.15 clearance eured of 0-l5cm So the ma' rs aasem bl have lesse cleaoce ort ther tolera

9-92 20.0 9.99

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