PSI - Issue 75

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ScienceDirect

Procedia Structural Integrity 75 (2025) 150–157 Structural Integrity Procedia 00 (2025) 000–000 Structural Integrity Procedia 00 (2025) 000–000

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© 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 presents fretting fatigue tests on 42CrMo4 + QT steel, combined with self-heating measurements. The thermal imaging technique was used for rapid evaluation of the fretting fatigue limit targeting minimal consumption of test samples. Tests with load ratios of R = − 1 and R = 0 were performed using two di ff erent fretting pad designs. The fatigue limits resulting from temperature observations were compared with values obtained from conventional fretting fatigue S-N curves. Elastic-plastic simulations of the experiments were conducted, and multiaxial fatigue criteria were applied to assess the risk of crack initiation. Additionally, a qualitative assessment was made to predict crack initiation locations according to observations from fractography. © 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: fretting fatigue; self-heating method; thermography; fatigue limit; multiaxial fatigue criteria; fractography; FEA Fatigue Design 2025 (FatDes 2025) Application of self-heating method for characterization of 42CrMo4 + QT steel under fretting fatigue conditions Toma´sˇ Karas a, ∗ , Martin Matusˇu˚ a,b , Vladim´ır Ma´ra a , Martin Nesla´dek a , Jan Papuga a a Czech Technical University in Prague, Faculty of Mechanical Engineering, Technicka´ 4, 16607 Praha 6, Czech Republic b Department of Mechanical and Environmental Engineering, OTH Amberg-Weiden, Kaiser-Wilhelm-Ring 23, Amberg 92224, Germany Abstract This paper presents fretting fatigue tests on 42CrMo4 + QT steel, combined with self-heating measurements. The thermal imaging technique was used for rapid evaluation of the fretting fatigue limit targeting minimal consumption of test samples. Tests with load ratios of R = − 1 and R = 0 were performed using two di ff erent fretting pad designs. The fatigue limits resulting from temperature observations were compared with values obtained from conventional fretting fatigue S-N curves. Elastic-plastic simulations of the experiments were conducted, and multiaxial fatigue criteria were applied to assess the risk of crack initiation. Additionally, a qualitative assessment was made to predict crack initiation locations according to observations from fractography. © 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: fretting fatigue; self-heating method; thermography; fatigue limit; multiaxial fatigue criteria; fractography; FEA Fatigue Design 2025 (FatDes 2025) Application of self-heating method for characterization of 42CrMo4 + QT steel under fretting fatigue conditions Toma´sˇ Karas a, ∗ , Martin Matusˇu˚ a,b , Vladim´ır Ma´ra a , Martin Nesla´dek a , Jan Papuga a a Czech Technical University in Prague, Faculty of Mechanical Engineering, Technicka´ 4, 16607 Praha 6, Czech Republic b Department of Mechanical and Environmental Engineering, OTH Amberg-Weiden, Kaiser-Wilhelm-Ring 23, Amberg 92224, Germany Fretting fatigue presents a prevalent phenomenon in the engineering design of commonly used components such as shrink fits (Suchy´ et al. (2022)), spline couplings, and dovetail joints. Therefore, investigating non-conventional methods for characterising fretting fatigue behaviour is of significant interest. Traditional fatigue testing to define the S-N curve is time consuming and requires substantial material consumption. In comparison, the self-heating method presents a promising technique for fatigue characterisation and fatigue limit (FL) estimation (Matusˇu˚ et al. (2024)). It substantially reduces testing time while being less material-intensive. Among the materials widely used in engineering applications is 42CrMo4 + QT steel, a low-alloy medium carbon steel known for its high strength and hardness after quenching and tempering. It is a suitable choice for highly stressed parts in diverse industries, with the automotive and aerospace industries being the most prevalent. Especially in these industries, parts are also exposed to vibrations, small oscillatory motion, and wear (Nesla´dek et al. (2024)). Therefore, understanding the fretting fatigue behaviour of 42CrMo4 + QT steel is crucial to ensure its reliability and safety. Fretting fatigue presents a prevalent phenomenon in the engineering design of commonly used components such as shrink fits (Suchy´ et al. (2022)), spline couplings, and dovetail joints. Therefore, investigating non-conventional methods for characterising fretting fatigue behaviour is of significant interest. Traditional fatigue testing to define the S-N curve is time consuming and requires substantial material consumption. In comparison, the self-heating method presents a promising technique for fatigue characterisation and fatigue limit (FL) estimation (Matusˇu˚ et al. (2024)). It substantially reduces testing time while being less material-intensive. Among the materials widely used in engineering applications is 42CrMo4 + QT steel, a low-alloy medium carbon steel known for its high strength and hardness after quenching and tempering. It is a suitable choice for highly stressed parts in diverse industries, with the automotive and aerospace industries being the most prevalent. Especially in these industries, parts are also exposed to vibrations, small oscillatory motion, and wear (Nesla´dek et al. (2024)). Therefore, understanding the fretting fatigue behaviour of 42CrMo4 + QT steel is crucial to ensure its reliability and safety. 1. Introduction 1. Introduction

∗ Corresponding author. E-mail address: tomas.karas@fs.cvut.cz ∗ Corresponding author. E-mail address: tomas.karas@fs.cvut.cz

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.2025.11.017 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.