PSI - Issue 68

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

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Procedia Structural Integrity 68 (2025) 660–665

European Conference on Fracture 2024 Fatigue life predictions of notched samples based on average strain energy density Jan Klusák a *, Kamila Kozáková a,b

a Institute of Physics of Materials, Czech Academy of Science, Žižkova 513/22, 616 00 Brno, Czech Republic b Faculty of Mechanical Engineering, Brno University of Technology, Technická 289/2, 616 69 Brno, Czech Republic

Abstract The approach for fatigue lifetime predictions of notched specimens based on the theory of critical distances is modified to the use of strain energy density. Average values of strain energy density are used here to determine critical distances in dependence on number of cycles to failure (for fatigue loading). These values are modified to be used to predict the fatigue life of different notches. Classical critical distance theory uses the opening stress distribution (normal loading mode). The use of strain energy density allows other stress components to be included in the calculations. © 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: Strain energy density; fatigue life predictions; notches evaluation; theory of critical distances; 1. Introduction The theory of critical distances (TCD) opens possibilities for assessment of stress concentrations under static or cyclic fatigue loading. It is a powerful tool used for predicting fracture and fatigue of engineering components with stress concentrators, such as notches or cracks (Borges et al., 2019; Taylor, 2008). TCD was first proposed by Neuber (Neuber, 1958) and Peterson (Peterson, 1959). Over the years, various theories have arisen, and TCD has been rediscovered and reformulated with the increasing availability of computer-aided stress analysis (Susmel, 2008; © 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.: +420-532290348. E-mail address: klusak@ipm.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 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.2025.06.112