A circular cylindrical rod with a uniform cross-sectional area of 20 cm2 is subjected to a mean axial force of 120 kN. The fatigue strength of the material, σa = σfs, is 250 MPa after 106 cycles of fully reversed loading and σTS = 500 MPa. Using the different procedures discussed in this chapter, estimate the allowable amplitude of force for which the shaft should be designed to withstand at least one million fatigue cycles. State all your assumptions clearly.