The bar shown is subjected to a repeated moment of 0M700 lbf in. The bar is steel with Sur 120 ksi, Sy-66 ksi and Kic-55 ksiin. Material tests on various specimens of this material with identical heat treat treatment indicate worst-case constants of C = 3.2x10-11 (in/cycle)/(ksiVin) and m= 3.0. As shown nick of size 0.010 in has been discovered on the bottom of the bar. Estimate the number of cycles of life remaining. M -Nick 1. (Given) The stress range (67.2 ksi) is less than the yield strength. AMC AMC (700 lbf in)(0.25 in) I (0.25 in) (0.5 in) Ao = M (bh 12 2. Assuming =1, what is the final crack length a, before fracture? = 67.2 ksi 5 a