PSI - Issue 16

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

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Procedia Structural Integrity 16 (2019) 43–50

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the 6th International Conference “Fracture Mechanics of Materials and Structural Integrity” organizers. © 2019 The Author(s). Published by Elsevier B.V. Peer- review under responsibility of the 6th International Conference “Fracture Mechanics of Materials and Structural Integrity” organizers The paper presents the results of impact tests of standard Charpy specimens, sub-sized specimens, and side-grooved specimens made of steel 45. The instrumented vertical impact testing machine is used together with the system of high-speed recording of strain and forces. Based on the impact test results and the methods of quantitative fractography, the temperature dependences of the total specific energy of strain and fracture and its components are plotted: energy of the crack initiation, energy of the ductile crack growth, energy of the brittle crack jump, and energy of the ductile rupture area. Noteworthy is that the elimination of t e influence of shear lips in the determination of different characteristics (energy of the crack propagation, moment of the crack i itiatio ) defines the use of the side-grooved specimens instead of standard Charpy specimens. The authors have determined t e average velocities of the crack propagation in the typical fracture zones of the specimens of all types. The dependencies of the instantaneous velocity of the crack propagation on its length and time in standard Charpy specimens are determined using the tensile impact gauges. © 2019 The Author(s). Published by Elsevier B.V. Peer- review under responsibility of the 6th International Conference “Fracture Mechanics of Materials and Structural Integrity” organizers The paper presents the results of impact tests of standard Charpy specimens, sub-sized specimens, and side-grooved specimens made of steel 45. The instrumented vertical impact testing machine is used together with the system of high-speed recording of strain and forces. Based on the impact test results and the methods of quantitative fractography, the temperature dependences of the total specific energy of strain and fracture and its components are plotted: energy of the crack initiation, energy of the ductile crack growth, energy of the brittle crack jump, and energy of the ductile rupture area. Noteworthy is that the elimination of the influence of shear lips in the determination of different characteristics (energy of the crack propagation, moment of the crack initiation) defines the use of the side-grooved specimens instead of standard Charpy specimens. The authors have determined the average velocities of the crack propagation in the typical fracture zones of the specimens of all types. The dependencies of the instantaneous velocity of the crack propagation on its length and time in standard Charpy specimens are determined using the tensile impact gauges. Keywords: Charpy specimens; fracture energy; crack velocity; impact tests. 6th International Conference “Fracture Mechanics of Materials and Structural Integrity” Peculiarities of the crack initiation and propagation in different specimen types 6th International Conference “Fracture Mechanics of Materials and Structural Integrity” Peculiarities of the crack initiation and propagation in different specimen types Eugene Kondryakov*, Olexandr Panasenko, Andriy Kravchyk, Valeriy Kharchenko Eugene Kondryakov*, Olexandr Panasenko, Andriy Kravchyk, Valeriy Kharchenko Pisarenko Institute for Problems of Strength of the National Academy of Sciences of Ukraine, 2, Timiryazevs’ka St., Kyiv 01014, Ukraine Abstract Pisarenko Institute for Problems of Strength of the National Academy of Sciences of Ukraine, 2, Timiryazevs’ka St., Kyiv 01014, Ukraine Abstract

Keywords: Charpy specimens; fracture energy; crack velocity; impact tests.

* Corresponding author. E-mail address: kondryakov@ipp.kiev.ua * Corresponding author. E-mail address: kondryakov@ipp.kiev.ua

2452-3216 © 2019 The Author(s). Published by Elsevier B.V. Peer- review under responsibility of the 6th International Conference “Fracture Mechanics of Materials and Structural Integrity” organizers 2452-3216 © 2019 The Author(s). Published by Elsevier B.V. Peer- review under responsibility of the 6th International Conference “Fracture Mechanics of Materials and Structural Integrity” organizers

2452-3216  2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the 6th International Conference “Fracture Mechanics of Materials and Structural Integrity” organizers. 10.1016/j.prostr.2019.07.020