PSI - Issue 61

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2023) 000 – 000

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Procedia Structural Integrity 61 (2024) 268–276

3rd International Workshop on Plasticity, Damage and Fracture of Engineering Materials (IWPDF 2023) Fracture forming limit curve prediction by ductile fracture models Toros Arda Akşen a , Bora Şener b , Emre Esener c , Ümit Kocabıçak d , Mehmet F ı rat a, * 3rd International Workshop on Plasticity, Damage and Fracture of Engineering Materials (IWPDF 2023) Fracture forming limit curve prediction by ductile fracture models Toros Arda Akşen a , Bora Şener b , Emre Esener c , Ümit Kocabıçak d , Mehmet F ı rat a, *

a Department of Mechanical Engineering, The University of Sakarya, Sakarya 54050, Turkey b Department of Mechanical Engineering, Yıldız Technical University, İstanbul 34349, Turkey c Department of Mechanical Engineering, Bilecik Şeyh Edebali University, Bilecik 11210, Turkey d Department of Computer Engineering, The University of Sakarya, Sakarya 54050, Turkey a Department of Mechanical Engineering, The University of Sakarya, Sakarya 54050, Turkey b Department of Mechanical Engineering, Yıldız Technical University, İstanbul 34349, Turkey c Department of Mechanical Engineering, Bilecik Şeyh Edebali University, Bilecik 11210, Turkey d Department of Computer Engineering, The University of Sakarya, Sakarya 54050, Turkey

© 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 Abstract The fracture forming limit curve is an essential tool giving information about fracture initiation in metal forming applications. In order to obtain a fracture-forming limit curve, the Nakajima test should be carried out. However, these tests are costly and time consuming processes. Therefore, companies in the automotive industry tended to use non-expensive numerical approaches to determine the material’s formability limits. In this work, an anisotropic polynomial yield criterion was implemented to calib rate the different ductile fracture models, including only or both the stress triaxiality and the Lode parameter’s effect. Analy ses of different uniaxial tensile test geometries were carried out, and the two-dimensional fracture loci were constructed by different ductile fracture models. Correspondingly, the fracture-forming limit curves were predicted by the two-dimensional fracture loci. The results showed that the ductile fracture models, including only the stress triaxiality effect, provide an acceptable performance covering the range from uniaxial tension and the plane strain tension lines, while the models, including the stress triaxiality and Lode parameter, provide a plausible prediction performance throughout the whole range for forming limit diagram. © 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 Keywords: Ductile fracture model; fracture locus; forming limit curve Abstract The fracture forming limit curve is an essential tool giving information about fracture initiation in metal forming applications. In order to obtain a fracture-forming limit curve, the Nakajima test should be carried out. However, these tests are costly and time consuming processes. Therefore, companies in the automotive industry tended to use non-expensive numerical approaches to determine the material’s formability limits. In this work, an anisotropic polynomial yield criterion was implemented to calib rate the different ductile fracture models, including only or both the stress triaxiality and the Lode parameter’s effect. Analy ses of different uniaxial tensile test geometries were carried out, and the two-dimensional fracture loci were constructed by different ductile fracture models. Correspondingly, the fracture-forming limit curves were predicted by the two-dimensional fracture loci. The results showed that the ductile fracture models, including only the stress triaxiality effect, provide an acceptable performance covering the range from uniaxial tension and the plane strain tension lines, while the models, including the stress triaxiality and Lode parameter, provide a plausible prediction performance throughout the whole range for forming limit diagram. © 2024 The Authors. Published by ELSEVIER B.V. Keywords: Ductile fracture model; fracture locus; forming limit curve

* Corresponding author. Tel.: +90-264-295-5850. E-mail address: firat@sakarya.edu.tr * Corresponding author. Tel.: +90-264-295-5850. E-mail address: firat@sakarya.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 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

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.2024.06.034