PSI - Issue 68

ScienceDirect Structural Integrity Procedia 00 (2025) 000–000 Structural Integrity Procedia 00 (2025) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 68 (2025) 641–645

European Conference on Fracture 2024 The Two-parameter Fracture Criterion with Two-dimensional Crack Tip Front Constraint Yu.G. Matvienko a *, A. M. Pokrovskii b a Mechanical Engineering Research Institute of the Russian Academy of Sciences, 4 M. Kharitonievsky Per., Moscow 101000, Russia b Bauman Moscow State Technical University. 2-ya Baumanskaya ul., 5, Moscow 105005, Russia Abstract The present paper deals with crack-tip constraint parameters based on the nonsingular stresses which are included in the asymptotic stress field ahead of the crack tip front in the case of elastic behavior of the material. In the case of the asymptotic elastic stress field according to Williams, the nonsingular T xx and T zz stresses characterize two-dimensional constraint in the transverse ( Т xx ) and longitudinal ( Т zz ) directions along the crack front in three-dimensional solids. The fracture criterion is based on the maximum tangential stress which should be equal to the local strength in the fracture process zone ahead of the crack tip front. © 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 Keywords: crack-tip constraint, brittle fracture criterion, nonsingular T xx - and T zz -stresses 1. Introduction Recently, it has been proven that the fracture toughness is not a constant of the material, but it depends on geometry of the specimen, the crack aspect ratio, the thickness and the type of loading (e.g., Gupta et. al. (2015), Matvienko (2020). Models and criteria of two-parameter fracture mechanics make it possible to take into account the influence of specimen features on the fracture toughness by means of crack-tip constraint parameters. In this regard, in addition to the stress intensity factor, nonsingular terms of the Williams (1957) expansion for stresses, which are called T -stresses and characterized crack-tip constraint parameters in elastic materials, should be European Conference on Fracture 2024 The Two-parameter Fracture Criterion with Two-dimensional Crack Tip Front Constraint Yu.G. Matvienko a *, A. M. Pokrovskii b a Mechanical Engineering Research Institute of the Russian Academy of Sciences, 4 M. Kharitonievsky Per., Moscow 101000, Russia b Bauman Moscow State Technical University. 2-ya Baumanskaya ul., 5, Moscow 105005, Russia Abstract The present paper deals with crack-tip constraint parameters based on the nonsingular stresses which are included in the asymptotic stress field ahead of the crack tip front in the case of elastic behavior of the material. In the case of the asymptotic elastic stress field according to Williams, the nonsingular T xx and T zz stresses characterize two-dimensional constraint in the transverse ( Т xx ) and longitudinal ( Т zz ) directions along the crack front in three-dimensional solids. The fracture criterion is based on the maximum tangential stress which should be equal to the local strength in the fracture process zone ahead of the crack tip front. © 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 Keywords: crack-tip constraint, brittle fracture criterion, nonsingular T xx - and T zz -stresses 1. Introduction Recently, it has been proven that the fracture toughness is not a constant of the material, but it depends on geometry of the specimen, the crack aspect ratio, the thickness and the type of loading (e.g., Gupta et. al. (2015), Matvienko (2020). Models and criteria of two-parameter fracture mechanics make it possible to take into account the influence of specimen features on the fracture toughness by means of crack-tip constraint parameters. In this regard, in addition to the stress intensity factor, nonsingular terms of the Williams (1957) expansion for stresses, which are called T -stresses and characterized crack-tip constraint parameters in elastic materials, should be © 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

* Corresponding author. Tel.: +7-499-135-1204. E-mail address: ygmatvienko@gmail.com * Corresponding author. Tel.: +7-499-135-1204. E-mail address: ygmatvienko@gmail.com

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 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

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.2025.06.109