PSI - Issue 68

ScienceDirect Structural Integrity Procedia 00 (2025) 000–000 Structural Integrity Procedia 00 (2025) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com ScienceDirect

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

Procedia Structural Integrity 68 (2025) 815–821

European Conference on Fracture 2024 Quantification of Fatigue Life Improvement in S550MC Weldments by HFMI Treatment Using 2D SBFM Model M. Mahatab a, * , R. Ranjan a a Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, India Abstract In welded joint structures, most of the fatigue failure is triggered from the welded location due to the presence of a notch effect and high tensile residual stress at the weld toe resulting from the welding process. High-Frequency Mechanical Impact Treatment (HFMI) has been proven to be a well-known solution for the fatigue strength improvement of welded structures. However, only a selected grade of structural steel has been studied so far for fatigue strength improvement by the HFMI technique for specific applications. A high-strength S550MC steel grade is used for the fabrication of industrial large cranes and earth-moving equipment. There is a gap in the study of the use of the HFMI treatment to improve the fatigue performance for S550MC grade steel. This study focuses on the study of the effect of impact treatment on the fatigue performance of weldments made of S550MC steel. A numerical analysis has been carried out using the 2D Strain-Based Fracture Mechanics (SBFM) model on cruciform welded joints in as-welded and impact-treated conditions for constant amplitude (CA) and variable amplitude (VA) loading histories. Fatigue life prediction obtained for as-welded joints from the numerical analysis using the fracture mechanics model shows reasonable agreement with the CA experiment test results for the similar component geometry from the literature. The prediction from the model shows a significant improvement in fatigue strength due to HFMI treatment with assumed residual stress distribution under both CA and VA loading conditions. Therefore, the HFMI treatment technique and its applications have a strong potential for fatigue strength improvement of welded structures. © 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 ECF24 organizers Keywords: HFMI treatment; Fatigue crack growth model; Strain-based fracture mechanics; Post-weld treatment; High-strength steel European Conference on Fracture 2024 Quantification of Fatigue Life Improvement in S550MC Weldments by HFMI Treatment Using 2D SBFM Model M. Mahatab a, * , R. Ranjan a a Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, India Abstract In welded joint structures, most of the fatigue failure is triggered from the welded location due to the presence of a notch effect and high tensile residual stress at the weld toe resulting from the welding process. High-Frequency Mechanical Impact Treatment (HFMI) has been proven to be a well-known solution for the fatigue strength improvement of welded structures. However, only a selected grade of structural steel has been studied so far for fatigue strength improvement by the HFMI technique for specific applications. A high-strength S550MC steel grade is used for the fabrication of industrial large cranes and earth-moving equipment. There is a gap in the study of the use of the HFMI treatment to improve the fatigue performance for S550MC grade steel. This study focuses on the study of the effect of impact treatment on the fatigue performance of weldments made of S550MC steel. A numerical analysis has been carried out using the 2D Strain-Based Fracture Mechanics (SBFM) model on cruciform welded joints in as-welded and impact-treated conditions for constant amplitude (CA) and variable amplitude (VA) loading histories. Fatigue life prediction obtained for as-welded joints from the numerical analysis using the fracture mechanics model shows reasonable agreement with the CA experiment test results for the similar component geometry from the literature. The prediction from the model shows a significant improvement in fatigue strength due to HFMI treatment with assumed residual stress distribution under both CA and VA loading conditions. Therefore, the HFMI treatment technique and its applications have a strong potential for fatigue strength improvement of welded structures. © 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 ECF24 organizers Keywords: HFMI treatment; Fatigue crack growth model; Strain-based fracture mechanics; Post-weld treatment; High-strength steel © 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 ECF24 organizers

* Corresponding author. Tel.: +91-7007528595 E-mail address: mohd_m@ce.iitr.ac.in * Corresponding author. Tel.: +91-7007528595 E-mail address: mohd_m@ce.iitr.ac.in

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 ECF24 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 ECF24 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 ECF24 organizers 10.1016/j.prostr.2025.06.135