A shaft shown below is supported by bearings at each end, which have bores of 20.0 mm. The shaft material has the following material properties: Sy= 565 MPa and Sut = 676 MPa. The maximum fillet (R) permissible is 2.0 mm (see the sketch below). The surface is machined. Use a factor of safety of 3. Determine the diameter of the middle portion of the shaft. Consider the following individual load cases for shaft design: [a]. The load is steady and the shaft is stationary. [b]. The shaft is rotating - Use Goodman failure locus. Assume a reliability of 50%. [c]. The shaft is rotating and transmitting a torque of 150 N.m from the left bearing to the middle of the shaft. Use Goodman failure locus. d = 20mm 5.4 kN d = 20mm D = ? R Length not to scale a = ? -125 mm -250 mm-