(Solved): please provide steps A circular shaft is subject to a combination of loading as: - Constant shear st ...

A circular shaft is subject to a combination of loading as: - Constant shear stress of $56\mathrm{MPa}$ - Constant normal axial stress of $70\mathrm{MPa}$ - Completely reversible bending normal stress of $\pm 140\mathrm{Mpa}$ The ultimate tensile strength $S_{ut}=525\mathrm{MPa}$, yield strength $S_y=450\mathrm{MPa}$ and the fully corrected endurance limit $S_e=202\mathrm{MPa}$. The fatigue stress concentration factors ${\left({\mathrm{k}}_{\mathrm{f}}\right)}_{\mathrm{ax}}={\left({\mathrm{k}}_{\mathrm{f}}\right)}_{\mathrm{bend}}={\left({\mathrm{k}}_{\mathrm{f}}\right)}_{\text{tor }}=1.2$ 1-Determine the design factor $\left(n_f\right)$ for infinite life against fatigue failure using Goodman criteria. If $n_f<1$ determine the fatigue life cycles $(N)$ 2- Determine $n_y$ to check for first cycle yield