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) 375–381 Structural Integrity Procedia 00 (2025) 000–000 Structural Integrity Procedia 00 (2025) 000–000

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Fatigue Design 2025 (FatDes 2025) A Non-conventional Fracture Mechanics-based Multiaxial Fatigue Assessment of Defective and Sharply Notched Metallic Materials Francesco Collini a , Daniele Rigon a , Giacomo Severin a , Riccardo Montagner a , Giorgio Valsecchi b , Davide Zanchetti b , Giuseppe De Marco c , Simone Turani d , Giovanni Meneghetti a, ∗ Fatigue Design 2025 (FatDes 2025) A Non-conventional Fracture Mechanics-based Multiaxial Fatigue Assessment of Defective and Sharply Notched Metallic Materials Francesco Collini a , Daniele Rigon a , Giacomo Severin a , Riccardo Montagner a , Giorgio Valsecchi b , Davide Zanchetti b , Giuseppe De Marco c , Simone Turani d , Giovanni Meneghetti a, ∗

a Department of Industrial Engineering, University of Padova, Padova, 35131, Italy b TAV Vacuum Furnaces S.p.A., via dell’industria 11 – 24043, Caravaggio (BG), Italy c Kilometro Rosso S.p.A., via Stezzano 87 – 24126, Bergamo, Italy d Brembo S.p.A, Via Brembo, 25 - 24035 Curno (BG), Italy a Department of Industrial Engineering, University of Padova, Padova, 35131, Italy b TAV Vacuum Furnaces S.p.A., via dell’industria 11 – 24043, Caravaggio (BG), Italy c Kilometro Rosso S.p.A., via Stezzano 87 – 24126, Bergamo, Italy d Brembo S.p.A, Via Brembo, 25 - 24035 Curno (BG), Italy

© 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 © 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 Limit, V-notch; Multiaxial Fatigue; Strain Energy Density (SED); Linear Elastic Fracture Mechanics (LEFM); Additive Manufacturing field. By combining these two parameters using an El Haddad-Smith-Topper-type equation, defect sensitivity under local multiaxial stresses can be described. In a previous paper, an extensive validation against experimental multiaxial fatigue limits was performed on conventionally manufactured specimens, demonstrating a good correlation between theoretical estimations and experimental results. In this investigation, preliminary validation to additively manufactured specimens weakened by a net-shaped sharp V-notch subjected to multiaxial loading is included. © 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 Limit, V-notch; Multiaxial Fatigue; Strain Energy Density (SED); Linear Elastic Fracture Mechanics (LEFM); Additive Manufacturing Abstract The study addresses the engineering estimation of the multiaxial fatigue limit of components weakened by defects, cracks, and sharp U or V notches through a unified design criterion based on the Averaged Strain Energy Density (SED) approach, which extends the Atzori-Lazzarin-Meneghetti diagram to multiaxial loadings. The SED framework o ff ers a method to define both an equivalent defect-free material fatigue limit, denoted as ∆ σ 0 , eq , and an equivalent fatigue threshold, ∆ K V th,eq for any local stress field. By combining these two parameters using an El Haddad-Smith-Topper-type equation, defect sensitivity under local multiaxial stresses can be described. In a previous paper, an extensive validation against experimental multiaxial fatigue limits was performed on conventionally manufactured specimens, demonstrating a good correlation between theoretical estimations and experimental results. In this investigation, preliminary validation to additively manufactured specimens weakened by a net-shaped sharp V-notch subjected to multiaxial loading is included. Abstract The study addresses the engineering estimation of the multiaxial fatigue limit of components weakened by defects, cracks, and sharp U or V notches through a unified design criterion based on the Averaged Strain Energy Density (SED) approach, which extends the Atzori-Lazzarin-Meneghetti diagram to multiaxial loadings. The SED framework o ff ers a method to define both an equivalent defect-free material fatigue limit, denoted as ∆ σ 0 , eq , and an equivalent fatigue threshold, ∆ K V th,eq for any local stress

1. Introduction 1. Introduction

The study of multiaxial fatigue plays a crucial role in engineering and material science, as it determines the lifespan and performance of structures under complex stress conditions. The multiaxial fatigue behavior is influenced by a complex interplay of factors, including the loading path, the stress ratio, the material microstructure, the surface The study of multiaxial fatigue plays a crucial role in engineering and material science, as it determines the lifespan and performance of structures under complex stress conditions. The multiaxial fatigue behavior is influenced by a complex interplay of factors, including the loading path, the stress ratio, the material microstructure, the surface

∗ Corresponding author. Tel.: + 39-049-827-6751 E-mail address: giovanni.meneghetti@unipd.it ∗ Corresponding author. Tel.: + 39-049-827-6751 E-mail address: giovanni.meneghetti@unipd.it

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.2025.11.038 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.