Question

Chapter 08, Problem 8.23 Suppose that the fatigue data shown in the Animated Figure: S-N Plot for Brass is for a brass alloy that was tested using bending-rotating tests. A rod of this alloy is to be used for an automobile axle that rotates at an average rotational velocity of 700 revolutions per minute. Give the maximum bending stress amplitude possible for each of the following lifetimes of the rod: (a) 1 year, MPa [The tolerance is +/-1096] (b) 1 month, MPa [The tolerance is +/-10%) (c) 1 day MPa [The tolerance is +/-1090.]

Answer 1

An Suden Given that otation VeleityL alloy rm n ㅓ he maximum bending shers a amptlude are γγαχ, ,rnum be.n a. ime year 5600 min ime t) a 5, 25, 60o min's -Total Number叫cycles Ftorn c Ya.ph af γ 3.6 ×10g Cycle,Ş The tres p1Mpa 11 Mpa

(b) . Time -for l month 30x24 ×60 113,200 γηǐn . I (Time (t) z 시3,200 rnin Todal mumber of Cycles (n) NxE ·too ×ト13,200 お 3x1Dt Cycle onax hen Stress Amplittua 85 Mpa Ο '4 @wu -for lDay ad 1시시 0 min

"Total number of cyclef Nxt IXI0 Ccle Thum Stress ampl1 Time stress amp i ticle year 1 Month 1 Day 2s mpa 113 mpa