The aluminum plate shown below is subjected to cyclic loading with a far-field peak stress of O. The fatigue S-N curve and stress concentration information is also given below. The hole diameter d = 2.6 in. If the target fatigue life is 0.75 million cycles, the maximum far-field stress should be approximately Peak normal stress (ksi) 50 40 30 20 10 0 d O a. 11.2 ksi Ob. 7.4 ksi O.C. 10 71199 AP Aluminum Alloy 9.7 ksi P Steel Alloy Stress concentration factor K 5.00 10 10 10 Number of cycles on a log scale 4.00 3.00 2.00 1.00 10 in 0,00 0,10 O do O d. 6.5 ksi O e. 5.5 ksi 0.20 d/H ( 0.30 0.40 grow Kan 0.50 350 280 210 140 70 10.0 Peak normal stress (MPa)