PSI - Issue 42

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

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 42 (2022) 1040–1045

23 European Conference on Fracture - ECF23 Analogy between crack initiation due to dynamic pulse load and mass-spring system failure: fracture delay effect Yuri Petrov a , Nikita Kazarinov b *, Alexandr Utkin b

a Saint Petersburg State University, Universitetskaya emb. 7-9, Saint Petersburg 199034, Russia b Insitute of Problems of Mechanical Engineering, , Bolshoy av. 61, Saint Petersburg 199178, Russia

Abstract

© 2022 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 scientific committee of the 23 European Conference on Fracture – ECF23 In this short communication application of the incubation time fracture criterion (ITFC) for analysis of crack initiation under short pulse loading conditions is discussed. It is shown that the ITFC can be used to predict and investigate one of the key effects of the dynamic fracture – the fracture delay. The fracture delay phenomenon manifests itself when fracture occurs at a drop stage of local stress fields. In addition to this an analogy between crack instability under pulse loads and linear oscillator failure is drawn in the work. It is shown that the fracture process exhibits inertia when intensive loads are applied and a virtual oscillator with a particular eigen frequency can be formally attributed to a cracked sample. The applied theoretical models are calibrated against experimental data on crack onset under pulse loading conditions. © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 Keywords: Dynamic fracture; Pulse loads; crack initiation; fracture delay, incubation time, mass-spring model, inertia h

1. Introduction

If crack instability under quasistatic loading conditions is discussed, the Irwin’s fracture criterion is a reliable tool for fracture prediction, but if high rate loads are applied static critical SIF values have to be substituted by their dynamic counterparts having individual values for different loading rates ( "# ) (Ravi-Chandar and W.G. Knauss (1984)).

* Corresponding author. Tel.: +7-964-366-6464. E-mail address: nkazarinov@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 (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23

2452-3216 © 2022 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 scientific committee of the 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.131