PSI - Issue 30

ScienceDirect Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Procedia 00 (2020) 000–000 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Proc dia 00 (2020) 000–000 Available online at www.sciencedirect.com

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

Procedia Structural Integrity 30 (2020) 1–5

© 2020 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 EURASTRENCOLD - 2020 guest editors Abstract One of the little-studied problems of modern mechanics and the physics of fracture is the branching of the crack, which is observed in materials of a different nature. To experimentally determine the rate of crack branching velocity in steels, a series of tests were carried out on the fracture by internal pressure of steel thin-walled cylindrical shells (vessels) with measuring of the crack velocity by the method of breaking the conductive strips. A measurement setup was created on the basis of a precision converter “Tercon” signals of resistance thermometers and thermocouples, connected to a computer. Velocity measurements showed that in the case of straight-line propagation, the crack velocity is 350-541 m/s, and when crack branching, the crack velocity is 679-746 m/s. The results show that the crack branching velocity is a critical (limiting) crack propagation velocity, and the energy entering the top of a moving crack is not spent on increasing the crack velocity, but on creating new cracks by branching. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY- C-N license (h tps://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the EURASTRENCOLD - 2020 guest editors Keywords: Shell (vessel), steel, crack, branching, velocity. 1. Introduction Crack branching is one of the little-studied problems of modern mechanics and fracture physics, which is observed in various fracture processes and materials. The analysis of theoretical and experimental works dcarried out by Serensen et al. (1970), Finkel (1970), Ravi-Chandar and Knauss (1984), Kobayashi (1985), Sharon and Fineberg (1996), Bediy (1991), Naimark (2000), Uvarov (2000), Sheng (1999) shows that the parameter controlling Abstract One of the little-studied problems of modern mechanics and the physics of fracture is the branching of the crack, which is observed in materials of a different nature. To experimentally determine the rate of crack branching velocity in steels, a series of tests were carried out on the fracture by internal pressure of steel thin-walled cylindrical shells (vessels) with measuring of the crack velocity by the method of breaking the conductive strips. A measurement setup was created on the basis of a precision converter “Tercon” signals of resistance thermometers and thermocouples, connected to a computer. Velocity measurements showed that in the case of straight-line propagation, the crack velocity is 350-541 m/s, and when crack branching, the crack velocity is 679-746 m/s. The results show that the crack branching velocity is a critical (limiting) crack propagation velocity, and the energy entering the top of a moving crack is not spent on increasing the crack velocity, but on creating new cracks by branching. © 2020 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 esponsibility of the URASTRENCOLD - 2020 guest editors K ywords: Sh ll (vessel), steel, crack, branching, velocity. 1. Introduction Crack branching is one of the little-studied problems of modern mechanics and fracture physics, which is observed in various fracture processes and materials. The analysis of theoretical and experimental works dcarried out by Serensen et al. (1970), Finkel (1970), Ravi-Chandar and Knauss (1984), Kobayashi (1985), Sharon and Fineberg (1996), Bediy (1991), Naimark (2000), Uvarov (2000), Sheng (1999) shows that the parameter controlling IX Eurasian Symposium on the problems of strength and resource in low climatic temperatures (EURASTRENCOLD-2020) Experimental determination of crack velocities in steel A.A. Alexeev a, *, K.N. Bolshev a , V.A. Ivanov a , A.S. Syromyatnikova a , A.N. Kovalenko b a Larionov Institute of the Physical-Technical Problems of the North SB RAS, Yakutsk 677980, 1 Oktyabrskaya str., Russian Federation b Ioffe Institute, 26 Politekhnicheskaya, Saint Petersburg, 194021, Russian Federation IX Eurasian Symposium on the problems of strength and resource in low climatic temperatures (EURASTRENCOLD-2020) Experimental determination of crack velocities in steel A.A. Alexeev a, *, K.N. Bolshev a , V.A. Ivanov a , A.S. Syromyatnikova a , A.N. Kovalenko b a Larionov Institute of the Physical-Technical Problems of the North SB R S, Yakutsk 677980, 1 Oktyabrskaya str., Russian Federation b Ioffe Institute, 26 Politekhnicheskaya, Saint Petersburg, 194021, Russian Federation

* Corresponding author. Tel.: +791421042358; fax: +74112336665. E-mail address: spinor03@gmail.com * Corresponding author. Tel.: +791421042358; fax: +74112336665. E-mail address: spinor03@gmail.com

2452-3216 © 2020 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 EURASTRENCOLD - 2020 guest editors 10.1016/j.prostr.2020.12.001 2452-3216© 2020 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 the responsibility of the EURASTRENCOLD - 2020 guest editors 2452-3216© 2020 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 the responsibility of the EURASTRENCOLD - 2020 guest editors