PSI - Issue 75

Available online at www.sciencedirect.com Available online at www.sciencedirect.com Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 75 (2025) 435–441 Structural Integrity Procedia 00 (2025) 000–000 Structural Integrity Procedia 00 (2025) 000–000

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

© 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 The usage of ultra-high strength steels is ideal for thinner, lighter, and smarter solutions due to enhanced mechanical properties. These designs lead to weight reduction, consequent fuel and energy savings, higher payloads, and material cost savings. Target applications include but are not limited to yellow and green goods, trucks, tippers, cranes, and heavy mechanical equipment, where fatigue performance is critical in design due to cyclic service loads. Decreasing the thickness of current products for weight reduction results in increased stresses, which make the use of ultra-high strength steels essential as they o ff er have higher yield and tensile strengths and better fatigue resistance than conventional mild steels. Fatigue failure typically originates from stress raisers, which can be inherent in the microstructure, due to surface condition, or they result from joining, cutting, and forming procedures. In this study, we use an in-house fatigue testing setup to consider the complex e ff ect of cold forming in predicting number of cycles of a formed part. Finite-element analysis is used to predict the number of cycles. Utilizing a hybrid approach that combines experimental and numerical outputs, it is possible to define a design space to account for the e ff ects of forming parameters such as bending ratio and surface state. The accurate quantification of the e ff ect of cold forming on fatigue life is crucial for the applications with fatigue-critical formed sections and to optimize future designs. © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the Fatigue Design 2025 organizers. Keywords: fatigue; ultra high strength steel; forming; bending Fatigue Design 2025 (FatDes 2025) Fatigue life assessment of cold-formed ultra-high strength steel sections Okan Yılmaz a, ∗ , Dennis Van Hoecke a a ArcelorMittal Global R & D Gent - OCAS N.V., Pres. J.F. Kennedylaan 3, 9060 Zelzate, Belgium Abstract The usage of ultra-high strength steels is ideal for thinner, lighter, and smarter solutions due to enhanced mechanical properties. These designs lead to weight reduction, consequent fuel and energy savings, higher payloads, and material cost savings. Target applications include but are not limited to yellow and green goods, trucks, tippers, cranes, and heavy mechanical equipment, where fatigue performance is critical in design due to cyclic service loads. Decreasing the thickness of current products for weight reduction results in increased stresses, which make the use of ultra-high strength steels essential as they o ff er have higher yield and tensile strengths and better fatigue resistance than conventional mild steels. Fatigue failure typically originates from stress raisers, which can be inherent in the microstructure, due to surface condition, or they result from joining, cutting, and forming procedures. In this study, we use an in-house fatigue testing setup to consider the complex e ff ect of cold forming in predicting number of cycles of a formed part. Finite-element analysis is used to predict the number of cycles. Utilizing a hybrid approach that combines experimental and numerical outputs, it is possible to define a design space to account for the e ff ects of forming parameters such as bending ratio and surface state. The accurate quantification of the e ff ect of cold forming on fatigue life is crucial for the applications with fatigue-critical formed sections and to optimize future designs. © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the Fatigue Design 2025 organizers. Keywords: fatigue; ultra high strength steel; forming; bending Fatigue Design 2025 (FatDes 2025) Fatigue life assessment of cold-formed ultra-high strength steel sections Okan Yılmaz a, ∗ , Dennis Van Hoecke a a ArcelorMittal Global R & D Gent - OCAS N.V., Pres. J.F. Kennedylaan 3, 9060 Zelzate, Belgium

1. Introduction 1. Introduction

Ultra-high strength steels (UHSS) come with enhanced mechanical properties in comparison to mild steel grades. They are used increasingly for new designs that lead to weight reduction, consequent fuel and energy savings, higher payloads, and material cost reduction. Yellow and green goods are the typical applications such as trucks, tippers, cranes, and heavy mechanical equipment. To achieve weight reduction, the thickness of the current designs are de creased resulting in increased stress and so it is essential to use a material with higher mechanical properties such as yield strength and ultimate tensile strength and better fatigue resistance. Ultra-high strength steels (UHSS) come with enhanced mechanical properties in comparison to mild steel grades. They are used increasingly for new designs that lead to weight reduction, consequent fuel and energy savings, higher payloads, and material cost reduction. Yellow and green goods are the typical applications such as trucks, tippers, cranes, and heavy mechanical equipment. To achieve weight reduction, the thickness of the current designs are de creased resulting in increased stress and so it is essential to use a material with higher mechanical properties such as yield strength and ultimate tensile strength and better fatigue resistance.

∗ Corresponding author. Tel.: + 32-477-030917. E-mail address: okan.yilmaz@arcelormittal.com ∗ Corresponding author. Tel.: + 32-477-030917. E-mail address: okan.yilmaz@arcelormittal.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 the responsibility of Dr Fabien Lefebvre with at least 2 reviewers per paper 10.1016/j.prostr.2025.11.043 2210-7843 © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the Fatigue Design 2025 organizers. 2210-7843 © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the Fatigue Design 2025 organizers.