FATIGUE STRENGTH OF SHOT PEENED NOTCHED PARTS

It is well known that shot peening strongly increases the fatigue strength of machine elements and structural components. Anyway, the contribution of shot peening to fatigue strength is generally underestimated by engineering design codes. This is due to the difficulty of defining a general fatigue design approach able to correctly and quantitatively consider the effect of shot peening, in terms of residual stresses and surface work hardening. In the present work the main approaches for fatigue design are considered and applied to notched and shot peened specimens under different fatigue conditions. The results allow evidencing the criteria able to better consider the effect of shot peening and to underline the critical points related to the application of the mentioned criteria to shot peened parts.