PSI - Issue 68

Available online at www.sciencedirect.com Available online at www.sciencedirect.com Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 68 (2025) 1140–1146 Structural Integrity Procedia 00 (2024) 000–000 Structural Integrity Procedia 00 (2024) 000–000

www.elsevier.com / locate / procedia www.elsevier.com / locate / procedia

European Conference on Fracture 2024 Modelling of Hydrogen-Induced Failure in Polycrystalline Materials through a Strain Gradient Crystal Plasticity Framework Berkehan Tatli, Tuncay Yalc¸inkaya ∗ Department of Aerospace Engineering, Middle East Technical University, Ankara 06800, Tu¨rkiye Abstract Hydrogen-induced failure, which a ff ects a wide range of metals, occurs when hydrogen particles di ff use within the lattice struc ture of materials exposed to hydrogen-rich environments. Various studies on hydrogen-induced failure has demonstrated that the presence of hydrogen atoms significantly a ff ects crack initiation and propagation, leading to reductions in ductility, strength, tough ness, and fatigue life. Several theories have been proposed to explain the mechanisms involved in hydrogen-induced failure, such as hydrogen-enhanced plasticity and hydrogen-enhanced decohesion. These mechanisms connect hydrogen-induced damage to the interactions occurring between hydrogen and imperfections within the material. This study is used to model the hydrogen enhanced decohesion mechanism, focusing on hydrogen-induced intergranular failure as the primary failure mechanism. Presented novel framework integrates a strain gradient crystal plasticity model with a potential-based mixed-mode cohesive zone formulation and a stress-driven hydrogen transport model. To explore size and nonlocal e ff ects on hydrogen-induced failure, 3D polycrys talline representative volume elements (RVEs) with di ff erent initial hydrogen concentrations are simulated. The findings show that incorporating strain gradient e ff ects significantly increases hydrogen accumulation near grain boundaries, altering the failure path. © 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 ECF24 organizers. Keywords: Hydrogen-Induced Failure; Cohesive Zone Modelling; Strain Gradient Crystal Plasticity; Polycrystalline Materials European Conference on Fracture 2024 Modelling of Hydrogen-Induced Failure in Polycrystalline Materials through a Strain Gradient Crystal Plasticity Framework Berkehan Tatli, Tuncay Yalc¸inkaya ∗ Department of Aerospace Engineering, Middle East Technical University, Ankara 06800, Tu¨rkiye Abstract Hydrogen-induced failure, which a ff ects a wide range of metals, occurs when hydrogen particles di ff use within the lattice struc ture of materials exposed to hydrogen-rich environments. Various studies on hydrogen-induced failure has demonstrated that the presence of hydrogen atoms significantly a ff ects crack initiation and propagation, leading to reductions in ductility, strength, tough ness, and fatigue life. Several theories have been proposed to explain the mechanisms involved in hydrogen-induced failure, such as hydrogen-enhanced plasticity and hydrogen-enhanced decohesion. These mechanisms connect hydrogen-induced damage to the interactions occurring between hydrogen and imperfections within the material. This study is used to model the hydrogen enhanced decohesion mechanism, focusing on hydrogen-induced intergranular failure as the primary failure mechanism. Presented novel framework integrates a strain gradient crystal plasticity model with a potential-based mixed-mode cohesive zone formulation and a stress-driven hydrogen transport model. To explore size and nonlocal e ff ects on hydrogen-induced failure, 3D polycrys talline representative volume elements (RVEs) with di ff erent initial hydrogen concentrations are simulated. The findings show that incorporating strain gradient e ff ects significantly increases hydrogen accumulation near grain boundaries, altering the failure path. © 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 ECF24 organizers. Keywords: Hydrogen-Induced Failure; Cohesive Zone Modelling; Strain Gradient Crystal Plasticity; Polycrystalline Materials © 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

1. Introduction 1. Introduction

Hydrogen-induced failure, commonly referred to as hydrogen embrittlement, is a complex phenomenon a ff ectinga wide range of metals and has attracted considerable attention in recent years. This occurs when hydrogen atoms di ff use and migrate within the lattice structure of metallic materials in a hydrogen-producing environment. Experimental studies have shown that the presence of hydrogen within the lattice structure significantly impacts both the initiation and propagation of cracks, resulting in decreased ductility Barrera et al. (2018), strength Neeraj et al. (2012), fracture toughness Chatzidouros et al. (2018), and fatigue life Ronevich et al. (2016). Hydrogen-induced failure, commonly referred to as hydrogen embrittlement, is a complex phenomenon a ff ectinga wide range of metals and has attracted considerable attention in recent years. This occurs when hydrogen atoms di ff use and migrate within the lattice structure of metallic materials in a hydrogen-producing environment. Experimental studies have shown that the presence of hydrogen within the lattice structure significantly impacts both the initiation and propagation of cracks, resulting in decreased ductility Barrera et al. (2018), strength Neeraj et al. (2012), fracture toughness Chatzidouros et al. (2018), and fatigue life Ronevich et al. (2016).

∗ Corresponding author. Tel.: + 903122104258 ; fax: + 903122104250. E-mail address: yalcinka@metu.edu.tr ∗ Corresponding author. Tel.: + 903122104258 ; fax: + 903122104250. E-mail address: yalcinka@metu.edu.tr

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.2025.06.179 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 ECF24 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 ECF24 organizers.