PSI - Issue 19

Jan Presse et al. / Procedia Structural Integrity 19 (2019) 423–432 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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• For the coach peel load case on hybrid joined connections, the rivet contributes most to the fatigue strength for higher loads while the adhesive rather contributes to lower load ranges. The static and fatigue strength improves with the size of the rivet, especially for higher loads. • The estimation of the fatigue life of self-piercing riveted connections is based on the structural stress approach by Rupp. The structural stresses are calculated by the internal cross-section forces derived from FE-simulations. A comparison of the stress values from the modified calculation to material-specific SN-curves leads to an accurate estimation of the fatigue life for SPRs for a wide range of parameters. • To assess adhesively bonded connections beyond the multi-material connection, several configurations have been tested under quasi-static and cyclic loads. Therefore, the sheet thicknesses and the material properties of the assembled sheets have been varied for LS and CP configurations. • Since the effective stress approach has been successfully used for the fatigue life estimation of related structural adhesives it was adapted for the adhesive used in this study. The high scatter from the resulting SN-curve leads to an inaccurate estimation of fatigue life. That is why in the FE-simulation shell elements have been added on the free areas of the adhesive that is represented with solid elements. The maximum major principal stress on the shell elements is considered as cause for the crack initiation in the adhesive. A regression through the stress values and number of cycles resulting from the tests leads to a reference SN-curve with a low scattering. [1] Meschut, G.; Hahn, O.; Horstmann, S.; Esderts, A.; Sander, M. Betriebsfestigkeit stanzgenieteter Bauteile. Europäische Forschungsgesellschaft für Blechverarbeitung e.V. (EFB). 2016. [2] Rupp, A.; Storzel K.; Grubisic V. Computer-aided dimensioning of spot-welded automotive structures. SAE Technical Paper No. 950711. 1995. [3] Meschut, G.; Augenthaler. F. Hybridfügen von Mischbaustrukturen aus faserverstärkten Kunststoffen mit metallischen Halbzeugen IGF-Nr. 17618 N. 2015. [4] Schlimmer, M.; Barthel, C.; Bornemann, J.; Pauli, J.; Siebert, M.; Matzenmiller, A.; Fiolka, M.; Gerlach, S.; Mahnken, R.; Hentrich, M.; Hahn, O.; Jendrny, J.; Wißling, M.; Dilger, K.; Welters, T.; Gumbsh, P.; Andrieux, F.; Memhard, D.; Sun, D.-Z.; Thoma, K.; Nossek, M.; Sauer, M.; Hennemann, O.-D.; Brede, M.; Marzi, S.; Hesebeck, O. P 676 - Methodenentwicklung zur Berechnung von höherfesten Stahlklebverbindungen des Fahrzeugbaus unter Crashbelastung, Verlag und Vertriebsgesellschaft, 466 pp. 2008. [5] Wirth, C. Berechnungskonzept für die Klebflanschfestigkeit in Gesamtkarosseriemodellen. VDI-Verlag. 2004 [6] Hennemann, O.D.; Brede, M.; Nagel, C.; Hahn, O.; Jendmy, J.; Teutenberg, D.; Schlimmer, M.; Mihm, K.M. P 653 - Methodenentwicklung zur Berechnung und Auslegung geklebter Stahlbauteile für den Fahrzeugbau bei schwingender Beanspruchung. Verlag und Vertriebsgesellschaft. 2012. [7] Baumgartner, J.; Schmidt, H.; Rybar, G.; Melz, T.; Ernstberger, L.; Teutenberger, D.; Hahn, O.; Meschut, G.; Schneider, B.; Nagel, C. Auslegung von geklebten Stahlblechstrukturen im Automobilbau für schwingende Last bei wechselnden Temperaturen unter Berücksichtigung des Versagensverhaltens. FAT Schriftreihe, Bd. 290. 2016. [8] Matzenmiller, A.; Kurnatowski, B.; Hanselka, H.; Bruder, T.; Schmidt, H.; Mayer, B.; Schneider, B.; Kehlenbeck, H.; Nagel, C. ; Brede, M. P 796 Schwingfestigkeitsauslegung von geklebten Stahlbauteilen des Fahrzeugbaus unter Belastung mit variablen Amplituden. Verlag und Vertriebsgesellschaft. 2012. [9] Schmidt, H.; Baumgartner, J.; Melz, T. Fatigue assessment of joints using the local stress field. Materialwissenschaft & Werkstoffe 46:93-229. 2015. [10] Taylor, D. Geometrical effects in fatigue: a unifying theoretical model. Int. J. Fatigue 21. 1999. [11] Neuber, H. Kerbspannungslehre, 3. ed., Springer Verlag, 1958. Acknowledgments This study was funded by the European Union under the Horizon 2020 program, grant agreement number 723893. References