PSI - Issue 23

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000 – 000 ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 ScienceDirect Available online at www.sciencedirect.com

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Procedia Structural Integrity 23 (2019) 101–106

© 2019 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 ICMSMF organizers © 201 9 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 IC MSMF organizers. Fatigue growth of the crack may be retarded as a consequence of the fatigue crack closure occurrence. Complete understanding of the closure process and ability of its accurate assessment is in best interest of scientific and engineering community. In this paper, three-dimensional numerical model of M(T) specimen with straight crack front was created and subjected to loading at various load ratios from R = -1 to R = 0.1. Settings of input parameters such as element size, length of the crack growth, number of substeps and contact elements were adopted from two-dimensional analyses. Closure levels were determined by the method of first node behind the crack tip displacement monitoring. Closure level determination was performed locally for each node along the crack front, respecting the distribution of the stress intensity factor. Results were compared to experimental results and discussion on the reasons of fatigue crack front curvature was provided. © 201 9 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 IC MSMF organizers. 9th International Conference on Materials Structure and Micromechanics of Fracture Numerical evaluation of plasticity induced crack closure in 3D structures Tomáš Oplt a,b *, Pavel Hutař b,c , Pavel Pokorný b , Luboš Náhlík c , Filippo Berto d a Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, Brno, Czech Republic b Institute of Physics of Materials of the Academy of Sciences of the Czech Republic, Žižkova 22, B rno, Czech Republic Czech Republic c CEITEC IPM, Institute of Physics of Materials of the Academy of Sciences of the Czech Republic, Žižkova 22, Brno, Czech Repub lic d Norwegian University of Science and Technology, NO-7491 Trondheim, Norway Fatigue growth of the crack may be retarded as a consequence of the fatigue crack closure occurrence. Complete understanding of the closure process and ability of its accurate assessment is in best interest of scientific and engineering community. In this paper, three-dimensional numerical model of M(T) specimen with straight crack front was created and subjected to loading at various load ratios from R = -1 to R = 0.1. Settings of input parameters such as element size, length of the crack growth, number of substeps and contact elements were adopted from two-dimensional analyses. Closure levels were determined by the method of first node behind the crack tip displacement monitoring. Closure level determination was performed locally for each node along the crack front, respecting the distribution of the stress intensity factor. Results were compared to experimental results and discussion on the reasons of fatigue crack front curvature was provided. 9th International Conference on Materials Structure and Micromechanics of Fracture Numerical evaluation of plasticity induced crack closure in 3D structures Tomáš Oplt a,b *, Pavel Hutař b,c , Pavel Pokorný b , Luboš Náhlík c , Filippo Berto d a Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, Brno, Czech Republic b Institute of Physics of Materials of the Academy of Sciences of the Czech Republic, Žižkova 22, B rno, Czech Republic Czech Republic c CEITEC IPM, Institute of Physics of Materials of the Academy of Sciences of the Czech Republic, Žižkova 22, Brno, Czech Repub lic d Norwegian University of Science and Technology, NO-7491 Trondheim, Norway Abstract Abstract Keywords: plasticity induced crack closure, fatigue crack propagation, crack front curvature, finite element analysis Keywords: plasticity induced crack closure, fatigue crack propagation, crack front curvature, finite element analysis 1. Introduction Basic but still most common fatigue lifetime evaluation of the propagating crack in engineering community is performed by using Paris- Erdogan’s law. Input parameter describing the crack load is the stress intensity range (SIF) 1. Introduction Basic but still most common fatigue lifetime evaluation of the propagating crack in engineering community is performed by using Paris- Erdogan’s law. Input parameter describing the crack load is the stress intensity range (SIF)

* Corresponding author. Tel.: +420 532 290 347 E-mail address: oplt@ipm.cz * Corresponding author. Tel.: +420 532 290 347 E-mail address: oplt@ipm.cz

2452-3216 © 2019 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 IC MSMF organizers. 2452-3216 © 2019 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 IC MSMF organizers.

2452-3216 © 2019 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 ICMSMF organizers 10.1016/j.prostr.2020.01.070