Fatigue Limit of Metal Cutting Machined Components

For the development of structural components, the importance of calculating the fatigue strength has steadily increased during recent years. The current state of the art in the catalog of technical rules on surface effects is based on results which were obtained 50 years ago. They aren't to be able to describe the current state of the surface layer which is manufactured by modern production processes. The present investigation shows, that the acknowledgement of the residual stress state is required for description of the influence of the machined surface to the fatigue strength. A concept is proposed and verified, for accurately calculating the fatigue strength, provided that the static strength, the surface topography and the residual stresses are known. A proposal for estimation the residual stress factor for adverse residual stress state by the shear stress intensity hypothesis (SIH), delivers good results.