Question 3 (continued) (30 marks) (b) A shaft A, made of AISI 1010 hot-rolled steel with a Brinell hardness, HB >200, is welded to a fixed support and is subjected to loading by equal and opposite forces F via shaft B as shown in Fig. 3(b). A theoretical stress concentration, Kis 1.6, is induced by the 3 mm = fillet. The length of shaft A from the fixed support to the connection at shaft B is 1 m. The total applied force F cycles from 0.5 to 2kN. Answer each of the following. (i) Calculate the fatigue factor of safety for infinite life using the modified Goodman fatigue failure criterion. (18 marks) (ii) Calculate the fatigue factor of safety for infinite life using the Gerber fatigue failure criterion. (2 marks) 3 mm fillet 20 mm Shaft A Fig. 3(b) F 25 mm 25 mm Shaft B