PSI - Issue 75

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

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 75 (2025) 530–537

Fatigue Design 2025 (FatDes 2025) Updated Guidelines on HFMI Treatment for Enhancing Fatigue

Strength in Welded Joints: IIW 2nd Edition Gary B. Marquis a , Zuheir Barsoum b, *, Martin Leitner c a Aalto University, Espoo, Finland b KTH Royal Institute of Technology, Stockholm, Sweden c Graz University of Technology, Graz, Austria a b c

© 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 Abstract This paper provides an overview of the second edition of the IIW recommendations on High-Frequency Mechanical Impact (HFMI) treatment, a widely recognized technique for enhancing the fatigue strength of welded joints. Based on extensive research and new experimental data, these updated guidelines introduce refined HFMI procedures, comprehensive fatigue assessment methods, and quality control measures. The recommendations are applicable to both new designs and the rehabilitation of existing structures, offering improved fatigue performance for steels with yield strengths ranging from 235 to 1300 MPa and thicknesses between 5 and 50 mm. Key considerations include expanding the recommendations on the effects of variable amplitude loading and the benefits of HFMI for high-strength steels. This version also introduces provisions for treating prefatigued and in-service structures, further extending the applicability of HFMI treatment. © 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: Post-weld treatment; Peening; High-frequency mechanical impact; Weld toe; Fatigue improvement; High strength steels; Fatigue strength; Structural rehabilitation. strength; Structural rehabilitation.

* Corresponding author. Tel.: +46-70 230 43 42. E-mail address: zuheir@kth.se

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.2025.11.053