PSI - Issue 57

ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ

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

Procedia Structural Integrity 57 (2024) 290–297

© 2024 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 2023 organizers Abstract This study investigates the effect of high-peak loads on local relaxation of residual stress and fatigue damage in HFMI-treated high-strength steel welded joints. The finite element simulations are applied to consider the combined effect of geometry, material, and residual stress. This simulation model specifically contains the actual treated surface profile with material imperfections. As a result, the material imperfections highly influence the local elastic-plastic behavior under load conditions, including a high tensile and compressive peak load, thus the local relaxation of residual stress and fatigue damage. The results provide further understanding towards a robust modeling approach to the fatigue life estimation of HFMI-treated welds subjected to high-peak loads. © 2023 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 2023 organizers Keywords: Residual stress; relaxation; HFMI; high-strength steel; welded joints; surface profile; material imperfections 1. Introduction Lightweight high-strength steel structures are demanded in various industrial applications such as offshore structures, ships, and bridges. The engineering challenge for this demand is improving the fatigue strength of welded joints since it is equal regardless of steel grades in current rules and standards. An effective tool to improve fatigue strength is high-frequency mechanical impact (HFMI) treatment. Applying HFMI treatment introduces compressive Fatigue Design 2023 (FatDes 2023) Local relaxation of residual stress in HFMI-treated high-strength steel welded joints subjected to high-peak loads Yuki Ono a *, Heikki Remes a , Koji Kinoshita b , Halid Can Yıldırım c , Alain Nussbaumer d a Aalto University, P.O. BOX 14100 Aalto, Espoo 20240, Finland b Gifu University, 1-1 Yanagido, Gifu 501-1139, Japan c Aarhus University, Inge Lehmanns gade 10, Aarhus 8000 C, Denmark d Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 18, Lausanne CH-1015, Switerland Abstract This study investigates the effect of high-peak loads on local relaxation of residual stress and fatigue damage in HFMI-treated high-strength steel welded joints. The finite element simulations are applied to consider the combined effect of geometry, material, and residual stress. This simulation model specifically contains the actual treated surface profile with material imperfections. As a result, the material imperfections highly influence the local elastic-plastic behavior under load conditions, including a high tensile and compressive peak load, thus the local relaxation of residual stress and fatigue damage. The results provide further understanding towards a robust modeling approach to the fatigue life estimation of HFMI-treated welds subjected to high-peak loads. © 2023 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 2023 organizers Keywords: Residual stress; relaxation; HFMI; high-strength steel; welded joints; surface profile; material imperfections 1. Introduction Lightweight high-strength steel structures are demanded in various industrial applications such as offshore structures, ships, and bridges. The engineering challenge for this demand is improving the fatigue strength of welded joints since it is equal regardless of steel grades in current rules and standards. An effective tool to improve fatigue strength is high-frequency mechanical impact (HFMI) treatment. Applying HFMI treatment introduces compressive Fatigue Design 2023 (FatDes 2023) Local relaxation of residual stress in HFMI-treated high-strength steel welded joints subjected to high-peak loads Yuki Ono a *, Heikki Remes a , Koji Kinoshita b , Halid Can Yıldırım c , Alain Nussbaumer d a Aalto University, P.O. BOX 14100 Aalto, Espoo 20240, Finland b Gifu University, 1-1 Yanagido, Gifu 501-1139, Japan c Aarhus University, Inge Lehmanns gade 10, Aarhus 8000 C, Denmark d Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 18, Lausanne CH-1015, Switerland

* Corresponding author. Tel.: +358 504772203. E-mail address: yuki.ono@aalto.fi * Corresponding author. Tel.: +358 504772203. E-mail address: yuki.ono@aalto.fi

2452-3216 © 2023 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 2023 organizers 2452-3216 © 2023 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 2023 organizers

2452-3216 © 2024 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 2023 organizers 10.1016/j.prostr.2024.03.031