A steel part is loaded with a combination of bending, axial, and torsion such that the following stresses are created at a particular location: Bending Completely reversed, with a maximum stress of 60 MPa Axial Constant stress of 20 MPa Torsion Repeated load, varying from 0 MPa to 70 MPa Assume the varying stresses are in phase with each other. The part contains a notch such that Khending = 1.4, Kfasial= 1.1, and Krsion 2.0. The material properties 300 MPa and S, = 400 MPa. The completely adjusted endurance limit is found to be S160 MPa. Find the factor of safety for fatigue based on infinite life, using are the Goodman criterion. If the life is not infinite, estimate the number of cycles, using the Walker criterion to find the equivalent completely reversed stress. Be sure to check for yielding.
