PSI - Issue 65

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2024) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 65 (2024) 170–176

The 17th International Conference on MECHANICS, RESOURCE AND DIAGNOSTICS OF MATERIALS AND STRUCTURES (MRDMS 2023) Influence of the plasticity zone size at the crack tip on the cold resistance of structural steel Prokopyev L.A. a, *, Andreev Ya.M. a , Semenov S.O. a , Lukin E.S. b a Federal Research Centre “The Yakut Scientific Centre of the Siberian Branch of the Russian Academy of Sciences”, 2, Petrovskogo st., Yakutsk, 677000, Russian Federation b V.P. Larionov Institute of the Physical-Technical Problems of the North of the Siberian Branch of the Russian Academy of Sciences, 1, Oktyabrskaya st., Yakutsk, 677000, Russian Federation Problems of cold resistance of structural steels are noted. The disadvantages of the methods used to determine the operating temperature range of materials are noted. The problems that need to be solved to improve methods for assessing the cold resistance of materials are noted. The possibility of quantitatively assessing the effect of temperature on the size of the plastic zone, based on the data of the yield strength of the material, was investigated. Data on the temperature dependence of the yield stress for several materials are extrapolated using a thermally activated flow model. Based on these data, using the equations of linear fracture mechanics and the Mises criterion, the dimensions of the plastic zone were calculated, as an example. The calculation is carried out for five different materials, for two types of state: plane-stressed and plane-strained. According to the calculation results, practically no changes in the size of the plastic zone are observed for aluminum alloys. On the contrary, for steel grade “St.3”, a reduction in the size of the plastic zone is provided. The ongoing decrease in the plasticity of the zone may be one of the reasons for the change in the type of brittleness failure at low temperatures. In this case, there may be cases when, when the temperature drops to a certain threshold, it is necessary to replace the given calculation, taking into account the determination of the limit state of a material with a crack. It is proposed to use a dimensionless value equal to the ratio of the size of the plastic zone at low temperatures to the size of the plastic zone at t=20 ℃ . This indicator can quantitatively assess the effect of temperature on the size of the plastic zone, as one of the indicators of the cold resistance of the material. © 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 MRDMS 2023 organizers a b © 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 MRDMS 2023 organizers Abstract

* Corresponding author. Tel.: +7-968-154-8286. E-mail address: l.prokopyev@yandex.ru

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 MRDMS 2023 organizers

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 MRDMS 2023 organizers 10.1016/j.prostr.2024.11.027