PSI - Issue 75

Kalle Lipiäinen et al. / Procedia Structural Integrity 75 (2025) 19–28 Lipiainen et al./ Structural Integrity Procedia (2025)

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4. Discussion and Conclusions Studies with DED-Arc AM technique regarding fatigue performance showed high potential for including manufacturing quality via including imperfection sizes in FE analysis (Lipiäinen et al. (2024, 2025). The approach could be implemented in future for industrial cases. For initial design, converting imperfection size to factor on ideal geometry based on printing process, feature and local geometry would be feasible for stress analysis. L-PBF manufactured titanium components were tested by Afkhami et al. (2025) in as-built and shot blasted condition with presence of mild notch. FAT 120 MPa m = 3 was obtained in when as-built condition was tested and FAT 200 MPa m = 3 when shot blasting was applied. In this study, evaluation with FEA obtained local stresses resulted mean fatigue strength of glass peened EOS build specimens 500 MPa m = 3 and 250 MPa m = 3 for other test series. The surface treatments significantly influenced the component ’s fatigue performance. Treatments influence on residual stress state and surface roughness, peening coverage and internal imperfections. Interestingly, treatments do not correlate with numerical surface roughness data. However, it is clear that high surface texture together with lower compressive stress in the surface resulted in weaker fatigue performance with test series other than EOS G. The designed and manufactured component exceeded ultimate capacity requirements. Fatigue testing indicated high performance against dynamic loading especially when peening was performed with full coverage for specimen with high-build quality. The peening should be performed with high enough intensity for fatigue strength improvement. Based on the study, the L-PBF manufactured titanium components could be used in aviation when designed carefully. Manufacturing process should be verified for obtaining high-quality to acquire high mechanical performance. Acknowledgements The authors would like to thank Business Finland for funding the research via DREAMS project, Amecxi Oy for providing specimens and printing data and Stresstech Oy for providing residual stress measurements. References Bologna, O., Cecchel, S., Cornacchia, G., Avanzini, A., Sepe, R., Berto, F., & Razavi, N. (2024). Investigating post-processing impact on fatigue performance of LPBF Ti6Al4V with heat treatment, high pressure heat treatment, and dry electropolishing strategies. International Journal of Fatigue , 185 . https://doi.org/10.1016/j.ijfatigue.2024.108365 Bonneric, M., Saintier, N., El Khoukhi, D., & Bega, J. (2025). Influence of the defect size, type, and position on the High Cycle Fatigue behavior of Ti-6Al-4V processed by laser powder bed fusion. 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