Problem 2 (40 Marks) A rectangular bar is cut from an AISI 1020 CD steel that is 2.5 in wide and 0.375 in thick with a 0.5-in-dia. hole drilled through the center as depicted in figure below. The bar is loaded in push-pull fatigue by the axial forces Fa uniformly distributed across its width. a) Where is the critical location for the failure of the part? (5 Marks) b) Determine the endurance strength of the part. (10 Marks) c) Find the minimum factor of safety for fatigue based on infinite life for the following conditions (20 Marks): i. Fa = -6 kip to +6 kip ii. Fa = 0 kip to +10 kip d) If the life is not infinite, estimate the number of cycles. (5 Marks) Hint: Be sure to check for yielding. Use the modified Goodmen relation. 3/8-1 2.5 1020