PSI - Issue 75

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia (2025) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia (2025) 000 – 000

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

ScienceDirect

Procedia Structural Integrity 75 (2025) 616–624

© 2025 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 the responsibility of Dr Fabien Lefebvre with at least 2 reviewers per paper © 2025 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 2025 organizers Keywords: Fatigue resistance ; weld imperfections ; undercut ; butt weld connections ; Eurocode 3 Abstract The design resistance in prEN 1993-1-9 for welded connections subject to fatigue loading refers to ISO 5817 quality level B. However, the background document does not explicitly support the link between weld quality level and fatigue resistance. To address this gap, an analysis was conducted on the experimental database used for prEN 1993-1-9, in conjunction with published results from literature encompassing over 1000 experimental fatigue tests. In addition, experimental tests were conducted on butt weld connections welded from one side to evaluate the impact of undercut on the fatigue strength. Non-destructive testing methods, including 3D scanning and radiographic testing, were employed to characterize weld imperfections. Fatigue strength was evaluated in accordance with prEN 1990 requirements. The findings revealed that mean undercuts height between 0.54 mm and 1.48 mm in a 15 mm plate thickness have decreased the fatigue strength to 62 MPa (13% reduction). Moreover, the use of 3D scanning provided detailed measurements of geometric imperfections that cannot be captured by visual inspection, which may downgrade the quality levels to D or below. This highlights the need to align weld quality classifications with the non-destructive test method employed. © 2025 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 2025 organizers Keywords: Fatigue resistance ; weld imperfections ; undercut ; butt weld connections ; Eurocode 3 Fatigue Design 2025 (FatDes 2025) Effect of undercut on the fatigue strength of butt weld connections Kevin Mouradian a,b *, André Beyer a , Maël Couchaux b , Mladen Lukić a , Fabrice Gatuingt c a Centre Technique Industriel de la Construction Métallique, 91190 Saint-Aubin, France b Institut National des Sciences Appliquées de Rennes, 35700 Rennes, France c Université Paris-Saclay, CentraleSupélec, ENS Paris-Saclay, CNRS, LMPS – Laboratoire de Mécanique Paris Saclay, 91190 gif-sur-Yvette, France Abstract The design resistance in prEN 1993-1-9 for welded connections subject to fatigue loading refers to ISO 5817 quality level B. However, the background document does not explicitly support the link between weld quality level and fatigue resistance. To address this gap, an analysis was conducted on the experimental database used for prEN 1993-1-9, in conjunction with published results from literature encompassing over 1000 experimental fatigue tests. In addition, experimental tests were conducted on butt weld connections welded from one side to evaluate the impact of undercut on the fatigue strength. Non-destructive testing methods, including 3D scanning and radiographic testing, were employed to characterize weld imperfections. Fatigue strength was evaluated in accordance with prEN 1990 requirements. The findings revealed that mean undercuts height between 0.54 mm and 1.48 mm in a 15 mm plate thickness have decreased the fatigue strength to 62 MPa (13% reduction). Moreover, the use of 3D scanning provided detailed measurements of geometric imperfections that cannot be captured by visual inspection, which may downgrade the quality levels to D or below. This highlights the need to align weld quality classifications with the non-destructive test method employed. Fatigue Design 2025 (FatDes 2025) Effect of undercut on the fatigue strength of butt weld connections Kevin Mouradian a,b *, André Beyer a , Maël Couchaux b , Mladen Lukić a , Fabrice Gatuingt c a Centre Technique Industriel de la Construction Métallique, 91190 Saint-Aubin, France b Institut National des Sciences Appliquées de Rennes, 35700 Rennes, France c Université Paris-Saclay, CentraleSupélec, ENS Paris-Saclay, CNRS, LMPS – Laboratoire de Mécanique Paris Saclay, 91190 gif-sur-Yvette, France

* Corresponding author. Tel.: +33 1 60 13 83 74 E-mail address: kmouradian@cticm.com * Corresponding author. Tel.: +33 1 60 13 83 74 E-mail address: kmouradian@cticm.com

2452-3216 © 2025 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 2025 organizers 2452-3216 © 2025 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 2025 organizers

2452-3216 © 2025 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 the responsibility of Dr Fabien Lefebvre with at least 2 reviewers per paper 10.1016/j.prostr.2025.11.063