A cylindrical 1045 steel bar (Figure 8.20) is subjected to repeated compression-tension stress cycling along its axis.

Question:

A cylindrical 1045 steel bar (Figure 8.20) is subjected to repeated compression-tension stress cycling along its axis. If the load amplitude is 23,000 N, calculate the minimum allowable bar diameter (in mm) to ensure that fatigue failure will not occur. Assume a factor of safety of 2.0.

(A) 19.4 mm

(B) 9.72 mm

(D) 13.7 mm