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Problem 2 The rohating steel shaft shown is simply supported at bearings A and B. The shaft has a circular cross-sections of diameter d and D=1.2d whero d is unknown. Two gears are mounted on section C and E. The torque, T. transmitted by the gears through the shaft (along CE ) varies from Ttin=2000 Ibfin and Ttar=+6000IbCin Two constant transverse loads with equal magnitudes P=3000lb act at sections C and E. The material properties of the shaft: Sx=140kpsi and Sy=120kpsi, and the fully corrected endurance limit, S8=60 kpsi. The fatigue stress concentration factors at the shoulders are Kf=1.6 and K=1.4. Note: Torque is Not constant. (a) Sketch the shear, bending and torque diagrams (use the axes below). [3 marks] (b) At the critical section (E), determine the altemating and midrange bending and shear stresses as a [5 matle] function of the smaller shaft diameter (d) (c) Determine the midrange and alternating Von Mises stresses as a function of the smaller shaft [2 murks] diameter (d) (d) If the fatigue factor of safety nf=2 based on the Goodman criterion, determine the diameter d. [3. mariks] If the first cycle yielding factor, ny=2, determine the diameter d. [2 marki]