Question

Problem 2: A hot-rolled shaft shoulder has a large diameter D is 45 mm, the small diameter d is 30 mm, and the fille (notch) radius is 3 mm. The bending moment, and the steady torsion moments are 100 N.m, and 75 N. respectively. The reliability goal for the endurance limit is 0.90. If the shaft is made of AISI 1030 hot-roll steel, (a) Determine the fatigue stress concentration factors (Ks, and Ks). (b) Determine endurance limit (Se). (c) Determine the factor of safety using appropreate theory

Answer 1

Given Material – AISI 1630 Chot rolled Steel) By Material Propo & Seet = SQ5MPa Syt = 440 MPa D- 45 mm d = 30mm match vado (0) = 3 mm Torque (T) = 75Nm Moment (M)=100N-m + 21 0-45= 1.5 Kts=1.45 K4 = 1.7| old old

old (a) Old - Notch sensitivity Kf-1 - 1.71 Kf-1 kt-1 Kts 1 1.45-1 * 12 kis-1 +/kfs=1.45| (6) - for (Kf = 1.56] Realiabieity goal 0.9 K = 0.897 kf I enderrance limit ist. K10.5 Sut) = 0.897%0.5x595 1.56 = 150.9MP & Ise=150.9MPa

(C)

T = 39M - 3ax100x100 - 37.79 MPO TIDST (30) = 16T = 16*75 X 103 = 14. 14 MPa id T (30) By von Misses + 102+372 - 07-12)+3149 Tra = 44• 97 MP2 o completelly Revereed stress + To ma T+02 zo $.07 2 I are some using Godmom loiterie May but opp-sign = + N = 150393 44.97 IN~ 3.4