PSI - Issue 57

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Procedia Structural Integrity 57 (2024) 461–468 Structural Integrity Procedia 00 (2023) 000–000 Structural Integrity Procedia 00 (2023) 000–000

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Fatigue Design 2023 (FatDes 2023) E ff ect of the grain boundary on the fatigue crack growth for aluminum bi-crystals. Fatigue Design 2023 (FatDes 2023) E ff ect of the grain boundary on the fatigue crack growth for aluminum bi-crystals.

Wilmer Velilla-D´ıaz a, ∗ , Habib R. Zambrano b a Universidad Austral de Chile, Gral. Lagos 2086, Valdivia 5110566, Chile b Universidad del Norte, Km 5 via Pto. Colombia, Barranquilla 081007, Colombia Wilmer Velilla-D´ıaz a, ∗ , Habib R. Zambrano b a Universidad Austral de Chile, Gral. Lagos 2086, Valdivia 5110566, Chile b Universidad del Norte, Km 5 via Pto. Colombia, Barranquilla 081007, Colombia

© 2024 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 2023 organizers © 2023 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 2023 organizers. Keywords: grain boundaries; fatigue crack growth; nanoscale; nanocrystalline material; bi-crystals Abstract Grain boundaries (GBs) are relevant as structural barriers for deformations in nano-crystalline materials and their resistance against fatigue crack propagation. The overall behavior of the material’s structure is the result of a complex confluence of multiple grains with a variety of relative orientations and their interaction with other structural defects. The e ff ect of the grain boundary on cracked grains is an important factor in order to establish the mechanical behavior of nano-materials under static and dynamic loading conditions. For studying the e ff ect of the grain boundary on the mechanical behavior of nano-crystalline solids a single boundary is placed as a defect that separates two miss-oriented crystals with a relative tilt or twist angle. The purpose of this study is to analyze the e ff ect of the GB and the relative tilt and twist angles on the crack propagation under increasing cyclic loading of cracked FCC bi-crystals. Molecular dynamics simulations at room temperature of fatigue crack growth tests were performed to characterize the retardation e ff ect of di ff erent grain miss-orientations on fatigue crack propagation. Al by-cristals with an initial edge crack and di ff erent miss-orientattion angles are simutalted, in the present research, under increasing cyclic loading condition. As a general trend high twist angles showed a greater e ff ect on the resistance to crack propagation under single and compound grain miss-orientation. © 2023 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 2023 organizers. Keywords: grain boundaries; fatigue crack growth; nanoscale; nanocrystalline material; bi-crystals Abstract Grain boundaries (GBs) are relevant as structural barriers for deformations in nano-crystalline materials and their resistance against fatigue crack propagation. The overall behavior of the material’s structure is the result of a complex confluence of multiple grains with a variety of relative orientations and their interaction with other structural defects. The e ff ect of the grain boundary on cracked grains is an important factor in order to establish the mechanical behavior of nano-materials under static and dynamic loading conditions. For studying the e ff ect of the grain boundary on the mechanical behavior of nano-crystalline solids a single boundary is placed as a defect that separates two miss-oriented crystals with a relative tilt or twist angle. The purpose of this study is to analyze the e ff ect of the GB and the relative tilt and twist angles on the crack propagation under increasing cyclic loading of cracked FCC bi-crystals. Molecular dynamics simulations at room temperature of fatigue crack growth tests were performed to characterize the retardation e ff ect of di ff erent grain miss-orientations on fatigue crack propagation. Al by-cristals with an initial edge crack and di ff erent miss-orientattion angles are simutalted, in the present research, under increasing cyclic loading condition. As a general trend high twist angles showed a greater e ff ect on the resistance to crack propagation under single and compound grain miss-orientation.

1. Introduction 1. Introduction

The rapid emergence of nano-electro-mechanical systems (NEMS) has raised the necessity of investigating deeper the mechanical behavior of nanomaterials, particularly in nanostructured thin films, in order to accurately estimate their thermal, electrical, and mechanical properties Berman and Krim (2013); Li and Bhushan (2003); Haque and Saif (2005). At the nanoscale, the presence and characteristics of grain boundaries (GBs) in nanocrystalline aluminum (Al) play a critical role in the mechanical behavior Meyers et al. (2006). The orientation of GBs has been identified The rapid emergence of nano-electro-mechanical systems (NEMS) has raised the necessity of investigating deeper the mechanical behavior of nanomaterials, particularly in nanostructured thin films, in order to accurately estimate their thermal, electrical, and mechanical properties Berman and Krim (2013); Li and Bhushan (2003); Haque and Saif (2005). At the nanoscale, the presence and characteristics of grain boundaries (GBs) in nanocrystalline aluminum (Al) play a critical role in the mechanical behavior Meyers et al. (2006). The orientation of GBs has been identified

∗ Corresponding author. Tel.: + 56-9-3788-2986. E-mail address: wilmer.velilla@uach.cl ∗ Corresponding author. Tel.: + 56-9-3788-2986. E-mail address: wilmer.velilla@uach.cl

2452-3216 © 2024 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 2023 organizers 10.1016/j.prostr.2024.03.050 2210-7843 © 2023 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 2023 organizers. 2210-7843 © 2023 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 2023 organizers.