A straight beam of solid and rectangular cross section made of AISI 4340 steel (Sut = 250 kpsi). The surface of the beam is ground to improve its fatigue life. The beam (non-rotating) is subjected to completely reversal bending moment of 1,400 lbf-inch. For d = 0.5 inch, D = 0.6 inch, r = 0.05 inch, b = 0.3 inch,f=0.77 (fatigue strength fraction of Sut at 1,000 cycles), estimate the number of cycles to fatigue failure of the notched beam. Ma K Ma 3.0 2.6 2.2 1.8 1.4 1.0 Side view (D) 1 b 0 1.05 3 0.05 1.1 1.3 Did-1.02 0.10 0.15 rfd D 0.20 d + 0.25 0.30