4. Problem 4: A shaft is loaded with 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 to 50 MPa. Assume the varying stresses are in phase with each other. The part contains a notch such that K+ bending-1.4, K+ axial= 1.1 and K+ torsion= 2.0. The material properties are S,= 300 MPa and Sur= 400 MPa. The corrected endurance limit is Se= 150 MPa. 4.1. Find the factor of safety for fatigue based on infinite life using the DE-Soderberg method and check for yielding. (5 Points) 4.2. If the same shaft is subjected to only a completely reversed nominal bending of 200 MPa. Find the fatigue safety factor using DE-Gerber. Is this an infinite life or finite life? Be sure to check for yielding. (5 Points)