PSI - Issue 34

Benjamin Möller et al. / Procedia Structural Integrity 34 (2021) 160–165 Author name / Structural Integrity Procedia 00 (2021) 000 – 000

165

6

5. Conclusions The following conclusions are drawn from the notch stress and structural stress fatigue assessment: - Notch stress assessment of specimens made of LBW between AlSi10Mg (AM) and EN AW-6082 T6 o Since notch stress amplitudes of LBW joints with I-shape seam welds and fillet welds diverge, an overall assessment is not reasonable. This can be traced back to the different failure types, i.e. at the notch root and weld toe, in combination with imperfections resulting from PBF-LB/M of AlSi10Mg. o Recommended notch stress FAT classes can only be applied to LBW lap joints with fillet welds. The slope of the design S-N curve of k = 5 for thin and flexible structures is confirmed. For investigated LBW joints with I-shape seam welds, either the weld quality needs to be improved or lower FAT classes should be assigned. - Structural stress assessment of the LBW aluminum component ‘battery carrier’ incl. AM node structures o Even though, the difference in fatigue life between the FE-based estimation and the experiment is sufficiently low, this result is an outcome of a specific modeling and meshing approach. A general validation is not given within this study. For a more detailed analysis on the basis of a modeling and meshing study, it is referred to Jöckel et al. (2021). A modeling and meshing guideline is essential. o Max. von Mises structural stresses, which are significantly higher than corresponding max. principal values, give rise to the presence of multiaxial loading situations, reasonable for welds of complex components. Other load cases, e.g. bending and torsion, are not included in the assessment approach. Acknowledgements The authors would like to thank the official organizations and all partners involved in the corresponding research and development project “VariKa” for their contributions. The research and development project “VariKa” that forms the basis for this publication is funded within the scope of the “PAiCE Digitale Technologien für die Wirtschaft” technology programme run by the Federal Ministry for Economic Affairs and Energy and is managed by the DLR projec t management agency „Gesellschaft, Innovation, Technologie - Informationstechnologien/ Elektromobilität“ at the German Aerospace Center in Cologne. The author is responsible for the content of this publication. 6. References Baumgartner J, Bruder T. An efficient meshing approach for the calculation of notch stresses. Weld World 57 (2013) 11, 137 – 145. https://doi.org/10.1007/s40194-012-0005-3 Chen L, Wang C, Xiong L, Zhang X, Mi G. Microstructural, porosity and mechanical properties of lap joint laser welding for 5182 and 6061 dissimilar aluminum alloys under different place configurations. Materials and Design 191 (2020) 108625. https://doi.org/10.1016/j.matdes.2020.108625 Jöckel A, Schnabel K, Baumgartner J, Möller B, Künkler B. Numerische Schwingfestigkeitsbewertung von Laserstrahlschweißverbindungen zwischen additiv und konventionell gefertigten Aluminiumblechen. Proceedings of the 47 th Annual Meeting of the DVM Working Group for Structural Durability “Arbeitskreis Betriebsfestigkeit”, 29 -30 September 2021, Kaiserslautern. (in German, in preparation) Kaufmann H, Sonsino CM, Petring D. Konstruktionsregeln und Betriebsfestigkeit lasergeschweißter Verbindungen aus Aluminium. LBF report no. 7852 (2000). (in German) Mäkikangas J, Rautio T, Mustakangas A, Mäntiyjärvi K. Laser welding of AlSi10Mg aluminium-based alloy produced by Selective Laser Melting (SLM). Procedia Manufacturing 36 (2019) 88 – 94. https://doi.org/10.1016/j.promfg.2019.08.013 Möller B, Bernhard J, Scurria M, Schnabel K, Melz T. Fatigue strength of additively manufactured and laser beam welded AlSi10Mg. Proceedings of the First European Conference on Structural Integrity of Additively Manufactured Materials (ESIAM19), 9 -11 September 2019, Trondheim. Möller B, Schnabel K, Wagener R, Kaufmann H., Melz T. Fatigue assessment of additively manufactured AlSi10Mg laser beam welded to rolled EN AW-6082 T6 sheet metal. Int J Fatigue 140 (2020) 105805. https://doi.org/10.1016/j.ijfatigue.2020.105805 Radaj D, Sonsino CM, Fricke W. Fatigue assessment of welded joints by local approaches. 2nd ed. Cambridge: Woodhead publishing, 2006. Störzel K, Bruder T, Hanselka H. Durability of welded aluminium extrusion profiles and aluminium sheets in vehicle structures. Int J Fatigue 34 (2012) 76 – 85. https://doi.org/10.1016/j.ijfatigue.2011.01.006 Schnabel K, Baumgartner J, Möller B, Scurria M. Fatigue assessment of additively manufactured AlSi10Mg structures using effective stress concepts based on the critical distance approach. Weld World (2021). https://doi.org/10.1007/s40194-021-01153-9 Wagener R, Möller B, Melz T, Scurria M. Deriving Strain Based Local Structural Element Concept for the Fatigue Assessment of Additively Manufactured Structures. SAE Technical Paper 2019-01-0525 (2019). https://doi.org/10.4271/2019-01-0525