Features of crack propagation in the elastic field of wedge disclination combined with edge superdislocation

S.V. Kirikov, V.N. Perevezentsev, A.S. Pupynin ORCID logo show affiliations and emails
Received 02 October 2024; Accepted 07 November 2024;
Citation: S.V. Kirikov, V.N. Perevezentsev, A.S. Pupynin. Features of crack propagation in the elastic field of wedge disclination combined with edge superdislocation. Lett. Mater., 2024, 14(4) 394-398
BibTex   https://doi.org/10.48612/letters/2024-4-394-398

Abstract

An abrupt increase in the crack size when the disclination strength exceed a critical valueThe parameters of a crack formed in the field of elastic stresses from a Somigliana dislocation, which is a superposition of a negative wedge disclination and an edge superdislocation, are analyzed. Analytical expressions are found out for the stress intensity factors at crack tips, describing their dependencies on the disclination strength, screening radius of its elastic field, Burgers vector of the superdislocation and crack parameters. Equilibrium crack configurations are calculated. It is shown that an increase in the disclination strength to a certain critical value leads to an abrupt increase in the crack size. In this case, a one-direction propagated crack located in the tensile stress zone of the superdislocation is transformed into a two-direction propagated crack located on both sides of the superdislocation, and the crack reaches sizes comparable with the screening radius of the elastic field of the disclination. At the initial stage, the crack is formed due to the field of elastic stresses from the superdislocation, and its further growth is carried out mainly due to the tensile elastic fields from the disclination. The dependence of the critical disclination strength on the Burgers vector of the superdislocation is obtained. It is concluded that the localization of dislocation and disclination charges in the same area of the structure leads to a synergistic effect in the formation of the microcrack.

References (37)

1. V. V. Rybin, Large plastic deformations and fracture of metals, Metallurgy, Moscow, 1986, 224 p. (in Russian) [В. В. Рыбин, Большие пластические деформации и разрушение металлов, Металлургия, Москва, 1986, 224 с.].
2. V. V. Rybin, V. A. Likhachev, A. N. Vergazov, Ductile fracture of molybdenum as a consequence of structural fragmentation, Phys. Metals Metallogr. 37 (1974) 620 - 624. (in Russian) [В. В. Рыбин, В. А. Лихачев, А. Н. Вергазов, Вязкое разрушение молибдена как следствие фрагментации структуры, ФММ 37 (1974) 620 - 624.].
3. A. N. Vergazov, V. A. Likhachev, V. V. Rybin, Characteristic elements of dislocation structure in deformed polycrystalline molybdenum, Phys. Metals Metallogr. 42 (1976) 146 -154. (in Russian) [А. Н. Вергазов, В. А. Лихачев, В. В. Рыбин, Характерные элементы дислокационной структуры в деформированном поликристаллическом молибдене, ФММ 42 (1976) 146 -154.].
4. V. V. Rybin, I. M. Zhukovsky, Disclination mechanism of microcrack formation, Phys. Solid State 20 (1978) 1829 -1835. (in Russian) [В. В. Рыбин, И. М. Жуковский, Дисклинационный механизм образования микротрещин, ФТТ 20 (1978) 1829 -1835.].
5. C. Zener, The micro-mechanism of fracture, in: Fracturing of metals, American Society for Metals, Clevland, 1948, p.3-31.
8. V. I. Vladimirov, Physical nature of metal fracture, Metallurgy, Moscow, 1984, 280 p. (in Russian) [В. И. Владимиров, Физическая природа разрушения металлов, Металлургия, Москва, 1984, 280 с.].
13. V. V. Rybin, Regularities of mesostructures development in metals in the course of plastic deformation, Probl. Mater. Sci. 33 (2003) 9 - 28.
25. M. Yu. Gutkin, I. A. Ovid’ko, N. V. Skiba, Generation of nanocracks at grain boundary disclinations in nanocomposite materials, Rev. Adv. Mater. Sci. 10 (2005) 483 - 489.
26. I. A. Ovid’ko, N. V. Skiba, Competition between nanoscale plastic deformation and fracture processes near triple junctions of grain boundaries in nanoceramics, Mater. Phys. Mech. 14 (2012) 101-109. (in Russian) [И. А. Овидько, Н. В. Скиба Конкуренция между процессами наномасштабной пластической деформации и разрушения вблизи тройных стыков границ зерен в нанокерамиках, Mater. Phys. Mech., 14 (2012) 101-109.].
33. A. N. Orlov, V. N. Perevezentsev, V. V. Rybin, Grain boundaries in metals, Metallurgy, Moscow, 1980, 156 p. (in Russian) [A. H. Орлов, B. H. Перевезенцев, В. В. Рыбин, Границы зерен в металлах, Металлургия, Москва, 1980, 156 с.].
34. V. M. Pestrikov, E. M. Morozov, Fracture mechanics of solids: Course of lectures, Profession, Saint Petersburg, 2002, 300 p. (in Russian) [В. М. Пестриков, Е. М. Морозов, Механика разрушения твердых тел: Курс лекций, Профессия, Санкт-Петербург, 2002, 300 с.].
37. N. N. Kalitkin, Numerical methods: a tutorial, BHV-Petersburg, Saint Petersburg, 2011, 585 p. (in Russian) [Н. Н. Калиткин, Численные методы: учебное пособие, БХВ-Петербург, Санкт-Петербург, 2011, 585 c.].

Funding

1. the state assignment to IAP RAS for fundamental scientific research for 2024 – 2026 - topic FFUF-2024-0031, No 1023032800130‑3‑2.3.2