III. FATIGUE PROBLEM (25%) The cold-drawn AISI 1040 steel bar shown in the figure 125125 axial load fluctuating between 28 kN in compression to 28 kN in tension. Estimate the fatigue subjected to a completely reversed factor of safety. 10 mm 6-mm Ka= a(54) a = =(f Su) (0.9x600)` 972 Se 300 AISI 1040 properties Sut 600 MPa Sy-500 MPa Consider f=0.9 ky=2.2 S'es as = 0.5 (600) = 300 Mfa b = ()() x = -0.3318 -0.3319 Ko 972 (600) Ka = 116.338 MPa ns. =?