(Solved): The shaft shown in the figure is machined from AISI 1040 CD steel. The shaft rotates at 1600rpm and ...

The shaft shown in the figure is machined from AISI 1040 CD steel. The shaft rotates at $1600\mathrm{rpm}$ and is supported in rolling bearings at $A$ and $B$. The applied forces are $F_1=1200\mathrm{lbf}$ and $F_2=2400\mathrm{lbf}$. Determine the minimum fatigue factor of safety ( $nf)$ based on achieving infinite life. If infinite life is not predicted, estimate the number of cycles $(M$ to failure. Also check for yielding. The minimum fatigue factor of safety is The number of cycles to failure is