PSI - Issue 38

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2021) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2021) 000–000

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ScienceDirect

Procedia Structural Integrity 38 (2022) 251–259

© 2021 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 the scientific committee of the Fatigue Design 2021 Organizers In order to identify the fatigue strength behavior under constant and variable, multiaxial loading, fatigue tests on adhesively butt bonded double hollow cylinder specimens with a thickness of the bonding of 0.3 mm have been performed under load control. The endurable damage sums according to the Palmgren-Miner hypothesis with a modified slope after the knee point of the Woehler line are determined and compared to data from the literature, they are significantly lower than th = 1. Non-proportional multiaxial loading ( = 90°) does not reduce the fatigue life compared to proportional ( = 0°). © 2021 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 the scientific committee of the Fatigue Design 2021 Organizers Keywords: variable amplitude fatigue; design and test spectra; damage accumulation; multiaxial loading; adhesiv bonding Abstract Adhesive bonding is commonly used in the manufacturing of vehicle bodies. A bond-line has the advantage that the joined flanges are stressed homogenously compared to a conventional spot-welded design. In addition, the bond-line provides a higher stiffness and better damping behavior. There exists still quite some uncertainty in the fatigue assessment of adhesively bonded joints due to a lack of reliable assessment approaches. This is especially true for the case of more complex in-service loading conditions as variable amplitude and multiaxial loading. For example, the experimentally determined actual damage sum in the literature shows a high scatter and is well below the theoretical value of one proposed by Palmgren-Miner. This uncertainty is typically countered by an over-dimensioning of the bond. In order to identify the fatigue strength behavior under constant and variable, multiaxial loading, fatigue tests on adhesively butt bonded double hollow cylinder specimens with a thickness of the bonding of 0.3 mm have been performed under load control. The endurable damage sums according to the Palmgren-Miner hypothesis with a modified slope after the knee point of the Woehler line are determined and compared to data from the literature, they are significantly lower than th = 1. Non-proportional multiaxial loading ( = 90°) does not reduce the fatigue life compared to proportional ( = 0°). © 2021 The Authors. Published by ELSE IER B.V. i is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) r-review under responsibility of th scientific committe of the Fatigue Design 2021 Organizers Keywords: variable amplitude fatigue; design and test spectra; damage accumulation; multiaxial loading; adhesiv bonding FATIGUE DESIGN 2021, 9th Edition of the International Conference on Fatigue Design Fatigue strength of adhesively butt-bonded hollow cylinders under multiaxial loading with constant and variable amplitudes Matthias Hecht a* , Jörg Baumgartner a,b , Karina Tews c , Serkan Çavdar c , Gerson Meschut c a Technical University of Darmstadt; Research Group System Reliability, Adaptive Structures, and Machine Acoustics SAM, Otto-Berndt Straße 2, 64287 Darmstadt, Germany b Fraunhofer LBF, Institute for Structural Durability and System Reliability, Bartningstraße 47, 64289 Darmstadt, Germany c Paderborn University, Laboratory for material and joining technology (LWF), Pohlweg 47-49, 33098 Paderborn, Germany Abstract Adhesive bonding is commonly used in the manufacturing of vehicle bodies. A bond-line has the advantage that the joined flanges are stressed homogenously compared to a conventional spot-welded design. In addition, the bond-line provides a higher stiffness and better damping behavior. There exists still quite some uncertainty in the fatigue assessment of adhesively bonded joints due to a lack of reliable assessment approaches. This is especially true for the case of more complex in-service loading conditions as variable amplitude and multiaxial loading. For example, the experimentally determined actual damage sum in the literature shows a high scatter and is well below the theoretical value of one proposed by Palmgren-Miner. This uncertainty is typically countered by an over-dimensioning of the bond. FATIGUE DESIGN 2021, 9th Edition of the International Conference on Fatigue Design Fatigue strength of adhesively butt-bonded hollo cylinders under ultiaxial loading ith constant and variable a plitudes atthias Hecht a* , Jörg Baumgartner a,b , Karina Tews c , Serkan Çavdar c , Gerson eschut c a Technical University of Darmstadt; Research Group System Reliability, Adaptive Structures, and Machine Acoustics SAM, Otto-Berndt Straße 2, 64287 Darmstadt, Germany b Fraunhofer LBF, Institute for Structural Durability and System Reliability, Bartningstraße 47, 64289 Darmstadt, Germany c Paderborn University, Laboratory for material and joining technology (LWF), Pohlweg 47-49, 33098 Paderborn, Germany

* Corresponding author. Tel.: +49 6151 705-431; fax: +49 6151 705-214. E-mail address: matthias.hecht@sam.tu-darmstadt.de * Corresponding author. Tel.: +49 6151 705-431; fax: +49 6151 705-214. E-mail address: matthias.hecht@sam.tu-darmstadt.de

2452-3216 © 2021 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 the scientific committee of the Fatigue Design 2021 Organizers 2452-3216 © 2021 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 the scientific committee of the Fatigue Design 2021 Organizers

2452-3216 © 2021 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 the scientific committee of the Fatigue Design 2021 Organizers 10.1016/j.prostr.2022.03.026