Areal fatigue strength assessment of cast aluminium surface layers

Fatigue behaviour of additively manufactured Ti-6Al-4V alloy: The role of defects on scatter and statistical size effect

“…For this reason, the area measure on the failure surface does not seem relevant. Other parameters such as the depth and the bottom curvature of the local surface valleys might be more significant [24,25].…”

Probabilistic Surface Layer Fatigue Strength Assessment of EN AC-46200 Sand Castings

“…Thus, many studies contribute to the surface roughness effect on fatigue strength, investigating machined surfaces obtaining periodic surface textures [24][25][26][27][28][29]. As in the literature [30,31] various analytical equations are introduced to characterise geometrical notches, these formulations are adapted to assess machined [32][33][34][35] or even cast [36][37][38], and more recently also additively manufactured [39] surfaces.…”

“…The presented sub-area analysis provides additional information about local roughness parameters, which focusses on more distinctive, and therefore more fatigue crack-initiating surface pits. A modification of Peterson´s stress concentration factor [31] and its application on investigated sand cast aluminium surfaces lead to an engineering feasible areal fatigue assessment approach, as presented in [36]. The modified stress concentration factor K t,mod , as introduced in [36], is given in Equation (1) and utilises the local surface pit depth Sv local , the mean value of the crack initiating cast surface pit depth Sv rev and an equivalent notch root radius ρ.…”

“…A modification of Peterson´s stress concentration factor [31] and its application on investigated sand cast aluminium surfaces lead to an engineering feasible areal fatigue assessment approach, as presented in [36]. The modified stress concentration factor K t,mod , as introduced in [36], is given in Equation (1) and utilises the local surface pit depth Sv local , the mean value of the crack initiating cast surface pit depth Sv rev and an equivalent notch root radius ρ. Taking the local notch sensitivity into account, the surface fatigue notch factor K f ,s can be subsequently evaluated.…”

“…However, such as localised information is in general not available for cast surface structures. Therefore, this concept is extended by a probabilistic approach as previously recommended in [36]. Moreover, the effect of sub-area size ought to be investigated to cover miscellaneous evaluation area magnitudes as well.…”