TY - JOUR

T1 - Structural-time nature of the dynamic instability of the fracture process

AU - Petrov, Yuri

AU - Kazarinov, Nikita

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Principal effects of dynamic instability of the fracture process are investigated. Particularly an issue of a dependence of stress intensity factor (K) on crack velocity (v) is discussed. Uniqueness, related to the given material, and even existence of this dependence has been a matter of discussion among researchers, since contradicting experimental results have been reported in the literature over last decades. In this paper results of numerical simulations of the crack propagation process are presented. A numerical scheme based on finite element method and incubation time fracture criterion was developed. Scattering of the K values during the propagation process is considered to be a feature principally related to a spatial-temporal nature of the fracture process. It is found that quasistatic loading is characterized by a small scatter of the K values and fitting of the data can be performed in order to obtain some well-known K - v curve. In the case of a pulse loading the scatter is much higher and it can be concluded that a wide range of K values correspond to a particular crack velocity and no unique continuous K - v curve can be associated with the process. These results are supported by well-known experimental observations. Thus, it is proved that the incubation time fracture criterion makes it possible to investigate dynamic crack propagation for a wide variety of loading conditions (quasistatic, high rate and short pulse loading) and only one extra material parameter - the incubation time is needed to predict a big variety of effects of the dynamic instability of the fracture process. This is a huge advantage comparing to a widespread approach, which involves complicated experimental determination of material strain rate dependencies and an a priori given K - v relationship.

AB - Principal effects of dynamic instability of the fracture process are investigated. Particularly an issue of a dependence of stress intensity factor (K) on crack velocity (v) is discussed. Uniqueness, related to the given material, and even existence of this dependence has been a matter of discussion among researchers, since contradicting experimental results have been reported in the literature over last decades. In this paper results of numerical simulations of the crack propagation process are presented. A numerical scheme based on finite element method and incubation time fracture criterion was developed. Scattering of the K values during the propagation process is considered to be a feature principally related to a spatial-temporal nature of the fracture process. It is found that quasistatic loading is characterized by a small scatter of the K values and fitting of the data can be performed in order to obtain some well-known K - v curve. In the case of a pulse loading the scatter is much higher and it can be concluded that a wide range of K values correspond to a particular crack velocity and no unique continuous K - v curve can be associated with the process. These results are supported by well-known experimental observations. Thus, it is proved that the incubation time fracture criterion makes it possible to investigate dynamic crack propagation for a wide variety of loading conditions (quasistatic, high rate and short pulse loading) and only one extra material parameter - the incubation time is needed to predict a big variety of effects of the dynamic instability of the fracture process. This is a huge advantage comparing to a widespread approach, which involves complicated experimental determination of material strain rate dependencies and an a priori given K - v relationship.

KW - Crack propagation

KW - Dynamic fracture

KW - FEM

KW - Incubation time

KW - K-v dependence

UR - http://www.scopus.com/inward/record.url?scp=85064685498&partnerID=8YFLogxK

U2 - 10.1016/j.prostr.2018.12.341

DO - 10.1016/j.prostr.2018.12.341

M3 - Conference article

AN - SCOPUS:85064685498

VL - 13

SP - 1620

EP - 1625

JO - Procedia Structural Integrity

JF - Procedia Structural Integrity

SN - 2452-3216

T2 - 22nd European Conference on Fracture, ECF 2018

Y2 - 25 August 2018 through 26 August 2018

ER -