PSI - Issue 82

Peter Haefele et al. / Procedia Structural Integrity 82 (2026) 174–181 Peter Haefele and Patrick Schwarz / Structural Integrity Procedia 00 (2026) 000–000

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4. Summary Under stresses below the yield strength, the location of crack initiation in NO30-15 and NO30-19 is dependent on the surface condition. In this context, surface roughness, hardness, and residual stress states act in mutual competition. At load levels that induce irreversible deformation, the surface condition is altered, leading to a reduction of roughness-induced stresses and, as observed for unnotched shear-cut specimens, to a homogenization of edge hardness. For notched specimens, the damage mechanisms identified in constant amplitude tests can be transferred to service-like loading conditions, indicating comparable fatigue mechanisms. Differences in the damage patterns between material specimens and rotors made from NO30-19 with laser-cut edges can be attributed to the high plastic deformation occurring at the notch ground of the saturation bridge during testing. Overall, the results demonstrate a good transferability of the fatigue mechanisms with respect to the observed damage patterns. Acknowledgements The authors wish to express their thanks for the funding of the FVA and the support of the project-accompanying committee. Part of the present work was developed within the framework of the research project "FVA 807 II Betriebsfestigkeitsverhalten von E-Band". The project was funded by AVIF e.V. Furthermore, the authors would like to thank the project partners for their helpful comments and especially for providing the sheets. References Bode, B., Brueckner-Foit, A., Zeismann, F., 2016. Quasi-static and cyclic failure behavior of electric sheet material. International Journal of Fatigue 82, 350-360. Dehmani, H., Brugger, C., Palin-Luc, T., Mareau, C., Koechlin, S., 2016. Experimental study of the impact of punching operations on the high cycle fatigue strength of Fe–Si thin sheets. International Journal of Fatigue 82, 721-729. Dittmann, F., Paetzold, I., 2018. FAT 306 Einfluss der Kantenbearbeitung auf die Festigkeitseigenschaften von Stahl- Feinblechen unter quasistatischer und schwingender Beanspruchung. FAT Forschungsvereinigung Automobiltechnik e.V. Du L., Zhou G., Liu J., Shi W., Bi Y., Cheng Z., Xue H., 2017. Fatigue cracking characterization of high grade non-oriented electrical steels. Journal of Wuhan University of Technology-Mater. Sci. 32, 1329-1335. Gottwalt-Baruth, A., Kubaschinski, P., Waltz, M., Tetzlaff, U., 2024. Influence of the cutting method on the fatigue life and crack initiation of non oriented electrical steel sheets. International Journal of Fatigue 180 108073. Gottwalt-Bruth, A., 2023. Mechanisches Ermüdungsverhalten von Elektroband. Doctoral thesis, Universität Bayreuth. Grosch, J., 2017 (7). Schadenskunde im Maschinenbau. utb GmbH. Haefele, P., Thum, M., Knerr, T., 2018. Life-Time-Assessment for Rotors for Electric Drives, International Conference on Engineering Science and Innovative Technology. Thailand, pp. 1-5. Paul, D., 2014. Lightweight design rotor with integrated cooling. ATZ extra The Project ThyssenKrupp In Car Plus, 34-37. Roesler, J., Harders, H., Bäcker, M., 2007 (5). Mechanical Behaviour of Engineer-ing Materials: Metals, Ceramics, Polymers, and Composites. Springer Fachmedien Wiesbaden GmbH, Braunschweig. Schayes, C., Vogt, J., Bouquerel, J., 2016. Cyclic plasticity mechanism of the M330-35A steel. International Journal of Fatigue 82, 530-539. Schwarz, P., Haefele, P., 2023. Influence of the machining conditions on the lifetime under cyclic loading of non-grain-oriented electrical steel strips, 13th International Electric Drives Production Conference (EDPC). Regensburg, Germany, 1-6. Schwarz, P., Haefele, P., 2025. Betriebsfestigkeit von Rotoren aus E-Band, 1663. Forschungsvereinigung Antriebstechnik e.V. (FVA). Schwarz, P., Langlois, T., Haefele, P., 2024. Fatigue behaviour of specimen and rotor lamellas of non-grain oriented electrical steel under constant and variable amplitude loading, VAL5 Fifth International Conference on Material and Component Performance under Variable Amplitude Loading. Dresden, Germany, 293-302. Schwarz. P., Haefele, P., 2022. Rissinitiierungsort von Elektroband in Abhängigkeit der plastischen Verformung. Tagungsband Werkstoffprüfung 2022, Werkstoffe und Bauteile auf dem Prüfstand. Dresden, Germany, 307-313. Thum, M., 2019. Betriebsfestigkeit E-Band. Entwicklung eines einheitlichen und aussagekräftigen Prüfverfahrens zur Bestimmung der Betriebsfestigkeit von Elektroband, 1335. Forschungsvereinigung Antriebstechnik e.V. (FVA). Thum, M., Basavarajappa, V., Haefele, P., 2021. Influence of edge cutting process on fatigue behaviour of spectrum loaded aluminum sheets. International Journal of Fatigue 150, 106330. Wupperman, C., Schoppa, A., 2005. Merkblatt 401: Elektroband und -blech. Stahl-Informations-Zentrum, Düsseldorf.