PSI - Issue 82

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2026) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2026) 000–000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 82 (2026) 174–181

© 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID organizers Abstract The study deals with the investigation and evaluation of failure cases from fatigue tests reported in several publications from the authors on the electrical steels NO30-15 and NO30-19. For both materials, load-dependent crack initiation sites are observed at the cut edges, which can be attributed to changes in the edge condition under plastic deformation. Notched specimens and components show no differences in the damage patterns between constant amplitude loading and variable amplitude loading. © 2026 The Authors. Copy from the contract: Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID organizers Keywords: Electrical steel strip, fatigue, fractography, edge condition 1. The material group electrical steel With the increasing electrification of the automotive industry, the importance of materials with optimized electromagnetic properties is continuously growing. A central role in this context is played by the group of electrical steels, which are used to manufacture the rotor and stator stacks of electric motors. This material group can be divided into two main subgroups: grain-oriented and non-grain-oriented electrical steels. The key distinction between these two lies in the orientation of the crystalline, which is established through recrystallization annealing after the rolling process. In non-grain-oriented electrical steels, the grains are randomly oriented, resulting in an approximately isotropic magnetic behaviour. Since stators and rotors are not manufactured as solid components but rather as stacks of insulated individual laminations, the low sheet thickness (typically between 0.1 mm and 1 mm) represents another 8th International Conference on Structural Integrity and Durability (ICSID2025) Fatigue cracks in specimens and rotors made from non-grain oriented electrical steel Peter Haefele a, *, Patrick Schwarz a a Faculty of Mobility and Technology University of Applied Science, Kanalstrasse 33, Esslingen D-73728, Germany Abstract The study deals with the investigation and evaluation of failure cases from fatigue tests reported in several publications from the authors on the electrical steels NO30-15 and NO30-19. For both materials, load-dependent crack initiation sites are observed at the cut edges, which can be attributed to changes in the edge condition under plastic deformation. Notched specimens and components show no differences in the damage patterns between constant amplitude loading and variable amplitude loading. © 2026 The Authors. Copy from the contract: Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID organizers Keywords: Electrical steel strip, fatigue, fractography, edge condition 1. The material group electrical steel With the increasing electrification of the automotive industry, the importance of materials with optimized electromagnetic properties is continuously growing. A central role in this context is played by the group of electrical steels, which are used to manufacture the rotor and stator stacks of electric motors. This material group can be divided into two main subgroups: grain-oriented and non-grain-oriented electrical steels. The key distinction between these two lies in the orientation of the crystalline, which is established through recrystallization annealing after the rolling process. In non-grain-oriented electrical steels, the grains are randomly oriented, resulting in an approximately isotropic magnetic behaviour. Since stators and rotors are not manufactured as solid components but rather as stacks of insulated individual laminations, the low sheet thickness (typically between 0.1 mm and 1 mm) represents another 8th International Conference on Structural Integrity and Durability (ICSID2025) Fatigue cracks in specimens and rotors made from non-grain oriented electrical steel Peter Haefele a, *, Patrick Schwarz a a Faculty of Mobility and Technology University of Applied Science, Kanalstrasse 33, Esslingen D-73728, Germany

* Corresponding author. Tel.: +49(0)711 397 3263 E-mail address: peter.haefele@hs-esslingen.de * Corresponding author. Tel.: +49(0)711 397 3263 E-mail address: peter.haefele@hs-esslingen.de

2452-3216 © 2026 The Authors. Copy from the contract: Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID organizers 2452-3216 © 2026 The Authors. Copy from the contract: Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID organizers

2452-3216 © 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID organizers 10.1016/j.prostr.2026.04.027