PSI - Issue 75

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia (2025) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia (2025) 000 – 000 Available online at www.sciencedirect.com Procedia Structural Integrity 75 (2025) 1–9

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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 Defects induced by the fabrication process, which are dependent on the input process parameters, remain a critical issue in the fatigue design of industrial components processed by Laser Powder Bed Fusion (L-PBF). The present work aims to use numerical simulations to assess the impact of typical L-PBF defects on the High Cycle Fatigue strength of a high-strength material. To do so, real defect geometries have been explicitly integrated in the simulations, using X-ray tomography observations of different defect populations of Ti64 alloy processed by L-PBF. The fatigue strengths in the presence of the different defects have then been determined numerically for different types of loadings (tension, torsion, and tension-torsion) by applying the Crossland multiaxial fatigue criterion. A non-local analysis of the calculated stress fields was also included in the calculation of the Fatigue Indicator Parameter in order to account for the severe stress gradients at the vicinity of defects. With this approach and by considering different loading directions, the fatigue strength anisotropy was assessed for two defect populations (gas pores and lack-of-fusion defects) for the considered loading types. Defects induced by the fabrication process, which are dependent on the input process parameters, remain a critical issue in the fatigue design of industrial components processed by Laser Powder Bed Fusion (L-PBF). The present work aims to use numerical simulations to assess the impact of typical L-PBF defects on the High Cycle Fatigue strength of a high-strength material. To do so, real defect geometries have been explicitly integrated in the simulations, using X-ray tomography observations of different defect populations of Ti64 alloy processed by L-PBF. The fatigue strengths in the presence of the different defects have then been determined numerically for different types of loadings (tension, torsion, and tension-torsion) by applying the Crossland multiaxial fatigue criterion. A non-local analysis of the calculated stress fields was also included in the calculation of the Fatigue Indicator Parameter in order to account for the severe stress gradients at the vicinity of defects. With this approach and by considering different loading directions, the fatigue strength anisotropy was assessed for two defect populations (gas pores and lack-of-fusion defects) for the considered loading types. Keywords: Laser Powder Bed Fusion (L-PBF) ; Defect ; Anisotropy ; Finite Element Analysis (FEA) Fatigue Design 2025 (FatDes 2025) Numerical investigation of the effect of defect population on the fatigue strength anisotropy of Ti64 fabricated by Laser Powder Bed Fusion S.S. Penkulinti a,b , N. Saintier a,b , M. Bonneric a,b* , T. Palin-Luc a,b , B. Verquin c , F. Lefebvre c , P. Ghys d a Arts et Métiers Institute of Technology, CNRS, Bordeaux INP, HESAM Université, I2M, UMR 5295, F-33400 Talence, France b Univ. Bordeaux, CNRS, Bordeaux INP I2M, UMR 5295, F-33400 Talence, France c CETIM, F-60300 Senlis, France d ALSTOM, F-93400 Talence, France Fatigue Design 2025 (FatDes 2025) Numerical investigation of the effect of defect population on the fatigue strength anisotropy of Ti64 fabricated by Laser Powder Bed Fusion S.S. Penkulinti a,b , N. Saintier a,b , M. Bonneric a,b* , T. Palin-Luc a,b , B. Verquin c , F. Lefebvre c , P. Ghys d a Arts et Métiers Institute of Technology, CNRS, Bordeaux INP, HESAM Université, I2M, UMR 5295, F-33400 Talence, France b Univ. Bordeaux, CNRS, Bordeaux INP I2M, UMR 5295, F-33400 Talence, France c CETIM, F-60300 Senlis, France d ALSTOM, F-93400 Talence, France Abstract Abstract

Keywords: Laser Powder Bed Fusion (L-PBF) ; Defect ; Anisotropy ; Finite Element Analysis (FEA)

* Corresponding author. E-mail address: matthieu.bonneric@ensam.eu

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 the scientific committee of the Fatigue Design 2025 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 the scientific committee of the Fatigue Design 2025 organizers * Corresponding author. E-mail address: matthieu.bonneric@ensam.eu

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.2025.11.001