A grounded 6 cm in diameter steel shaft has minimum properties of Sy 600 Mpa and Sut 800 Mpa. The shaft is subjected to a steady torsional moment of 500 Nm, an alternating torsional moment of 400 Nm, an alternating bending moment of 200 Nm and a steady axial force of 4 kN. Assume; Kf for bending-1.5, Kf for tension 1.4, and Kfs for torsion 1.8. Using Modified Goodman criterion what can you say about the shaft? Does it have an infinite life? Does it have a limited life, if yes, how many cycles? Does it fail because of yielding or fatigue first?