PSI - Issue 61

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ScienceDirect

Procedia Structural Integrity 61 (2024) 12–19 Structural Integrity Procedia 00 (2024) 000–000 Structural Integrity Procedia 00 (2024) 000–000

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© 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 IWPDF 2023 Chairman © 2024 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 IWPDF 2023. Keywords: dual-phase steel; phase field fracture; crystal plasticity Abstract Dual-phase (DP) steel’s spread in the industry has been fueled by its highly desirable qualities, which include a unique balance of strength and ductility, making it a valuable material for applications ranging from automotive manufacturing to construction. Despite the continued progress in the research of DP steels, the complex failure mechanisms at the microscale, resulting from the coexistence of brittle martensite phases within the ductile ferrite phase, remain an area of ongoing exploration. This study aims to investigate the microstructural evolution, as well as crack initiation and propagation, in DP steels at the microscale. In this context, to accurately capture the microstructural evolution of DP steels, a rate-dependent crystal plasticity formulation is utilized for the ferrite phase alongside a phenomenological isotropic J 2 plasticity model for the martensite phase. A novel ductile phase field fracture framework has been implemented to predict crack initiation and propagation, integrating both crystal plasticity and J 2 plasticity constitutive models with the phase field fracture model. Generic 3D polycrystalline Representative Volume Elements (RVEs) are created and simulated to analyze the trends influencing the failure behavior of DP steels. The numerical study includes examples with two di ff erent martensite volume fractions (15% and 37%), each characterized by varying random crystallographic orientation sets and morphologies. The obtained results suggest that despite the similarity in stress concentration regions within two di ff erent random orientation sets in a simulation with fixed volume fraction and morphology, the resulting crack paths exhibit significant di ff erences. Additionally, it is inferred that damage appears to accumulate at the junction points of the martensite islands. Moreover, an increase in the martensite volume fraction is found to diminish the influence of crystallographic orientation on the resultant crack path. Therefore, given the aforementioned findings, it is essential to analyze the microstructural evolution, as well as crack initiation and propagation in DP steels, utilizing appropriate material and fracture modeling frameworks at the microscale. © 2024 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 IWPDF 2023. Keywords: dual-phase steel; phase field fracture; crystal plasticity 3rd International Workshop on Plasticity, Damage and Fracture of Engineering Materials (IWPDF 2023) Phase Field Fracture Modelling of Crack Initiation and Propagation in Dual-Phase Microstructures Berkehan Tatli, Can Erdog˘an, Mehmed Emin O¨ zcan, Tuncay Yalc¸inkaya ∗ Department of Aerospace Engineering, Middle East Technical University, Ankara 06800, Tu¨rkiye Abstract Dual-phase (DP) steel’s spread in the industry has been fueled by its highly desirable qualities, which include a unique balance of strength and ductility, making it a valuable material for applications ranging from automotive manufacturing to construction. Despite the continued progress in the research of DP steels, the complex failure mechanisms at the microscale, resulting from the coexistence of brittle martensite phases within the ductile ferrite phase, remain an area of ongoing exploration. This study aims to investigate the microstructural evolution, as well as crack initiation and propagation, in DP steels at the microscale. In this context, to accurately capture the microstructural evolution of DP steels, a rate-dependent crystal plasticity formulation is utilized for the ferrite phase alongside a phenomenological isotropic J 2 plasticity model for the martensite phase. A novel ductile phase field fracture framework has been implemented to predict crack initiation and propagation, integrating both crystal plasticity and J 2 plasticity constitutive models with the phase field fracture model. Generic 3D polycrystalline Representative Volume Elements (RVEs) are created and simulated to analyze the trends influencing the failure behavior of DP steels. The numerical study includes examples with two di ff erent martensite volume fractions (15% and 37%), each characterized by varying random crystallographic orientation sets and morphologies. The obtained results suggest that despite the similarity in stress concentration regions within two di ff erent random orientation sets in a simulation with fixed volume fraction and morphology, the resulting crack paths exhibit significant di ff erences. Additionally, it is inferred that damage appears to accumulate at the junction points of the martensite islands. Moreover, an increase in the martensite volume fraction is found to diminish the influence of crystallographic orientation on the resultant crack path. Therefore, given the aforementioned findings, it is essential to analyze the microstructural evolution, as well as crack initiation and propagation in DP steels, utilizing appropriate material and fracture modeling frameworks at the microscale. 3rd International Workshop on Plasticity, Damage and Fracture of Engineering Materials (IWPDF 2023) Phase Field Fracture Modelling of Crack Initiation and Propagation in Dual-Phase Microstructures Berkehan Tatli, Can Erdog˘an, Mehmed Emin O¨ zcan, Tuncay Yalc¸inkaya ∗ Department of Aerospace Engineering, Middle East Technical University, Ankara 06800, Tu¨rkiye

∗ 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 © 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 IWPDF 2023 Chairman 10.1016/j.prostr.2024.06.003 2210-7843 © 2024 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 IWPDF 2023. 2210-7843 © 2024 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 IWPDF 2023.