PSI - Issue 76

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ScienceDirect

Procedia Structural Integrity 76 (2026) 50–58

© 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 FDMD 2025 chairpersons Keywords: Additive Manufacturing; Fatigue Life Prediction; Bimodal Weibull Analysis; Defect Characterization Abstract The fatigue performance of components produced via selective laser melting technology is strongly influenced by several factors as printing process parameters, build orientation and internal defects. This study investigates the fatigue behavior of AlSi10Mg spec imens with machined surfaces, emphasizing the unusually high variability in lifetimes observed in samples built in the Z direction. A refined Weibull statistical approach, accounting for defect-induced scatter and supported by fractographic analysis, is proposed. The novel bimodal probabilistic framework, calibrated through maximum likelihood estimation method, distinguishes between two dominant defect types—porosity and lack of fusion—enabling a more accurate description of fatigue life distributions. The model successfully captures defect-specific fatigue limits and o ff ers a robust method for integrating defect morphology into lifetime predictions, with strong implications for engineering design and reliability assessment of additively manufactured components. 5th International Symposium on Fatigue Design and Material Defects FDMD 2025 Enhanced Weibull Formulation for Capturing Fatigue Life Scatter in AM Alloys Supported by Fractographic Analysis Luca Esposito a, ∗ , Matteo Bruno a , Moreno Nacca b a Dept. of Chemical, Materials and Production Engineering, University of Naples Federico II, Napoli 80125, Italy b INFN, Sezione di Napoli, Italy

1. Introduction

Additive manufacturing (AM), particularly Selective Laser Melting (SLM), o ff ers substantial benefits for produc ing complex metallic components Herzog et al. (2016). However, fatigue performance remains a critical limitation, primarily due to process-induced internal defects such as gas porosity, keyhole porosity, inclusions, lack of fusion (LoF), and their anisotropic distribution within the build volume Seifi et al. (2017); Esposito et al. (2025). Among aluminum-based alloys, AlSi10Mg is widely employed in AM due to its good printability and mechanical properties Brandl et al. (2012a). Nevertheless, understanding and modeling the fatigue behavior of AlSi10Mg remains challenging, especially when accounting for anisotropy and defect variability introduced by di ff erent build orientations Esposito et al. (2025).

∗ Corresponding author. Tel.: + 39-081-768-2463 ; E-mail address: luca.esposito2@unina.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 responsibility of the scientific committee of the FDMD 2025 chairpersons 10.1016/j.prostr.2025.12.286