Paper on International Journal of Fatigue :: Open Access
https://doi.org/10.1016/j.ijfatigue.2025.108821
This study models the impact of surface roughness and pores on the fatigue strength of plain and V-notched Inconel 718 specimens produced via laser powder bed fusion, in both as-built and machined conditions. Fractographic analysis assessed porosity, while surface roughness was examined using an optical profilometer. Pore size and distance from the external surface were analyzed using Gumbel and exponential distribution functions. Finite element simulations of scanned surface profiles and pores were implemented, and the results were employed to calculate the fatigue stress concentration factors according to the theory of critical distances. This latter was calibrated by using the sharp and blunt V-notched specimens under machined condition. Finally, extreme value distributions were applied to estimate fatigue stress concentration factors of pores and surface roughness at 99% of probability. These latter were combined in a simplified way, and fatigue strength predictions of blunt V-notched as-built and plain machined and as-built specimens closely matched experimental data.
