Open AccessFracture Nucleation Phenomena and Thermally Activated Crack Dynamics in Monocrystals
Author(s) -
Leonardo Golubović,
Dorel Moldovan
Publication year - 2021
Publication title -
applied physics research
Language(s) - English
Resource type - Journals
eISSN - 1916-9647
pISSN - 1916-9639
DOI - 10.5539/apr.v13n1p42
Subject(s) - nucleation , materials science , fracture (geology) , growth rate , growth theory , monte carlo method , stress (linguistics) , ultimate tensile strength , condensed matter physics , chemical physics , molecular dynamics , composite material , mechanics , thermodynamics , chemistry , computational chemistry , physics , geometry , linguistics , statistics , mathematics , neoclassical economics , philosophy , economics
We explore irreversible thermally activated growth of cracks which are shorter than the Griffith length. Such a growth was anticipated in several studies [Golubović, L. & Feng, S., (1991). Rate of microcrack nucleation, Physical Review A 43, 5223. Golubović, L. & Peredera, A., (1995). Mechanism of time-delayed fractures, Physical Review E 51, 2799]. We explore this thermally activated growth by means of atomistic Monte-Carlo dynamics simulations of stressed monocrystals. This crack growth is stepwise. Each step is marked by nucleation of a microcavity close to the crack tip, and by creation of a passage connecting the microcavity and the crack. If the external tensile stress is weak, many such nucleation events occur before the crack length reaches the Griffith size. In addition to the simulations, we also present an analytic theory of the stepwise thermally activated crack growth. The theory explains surprising observation form our simulations that the thermally activated crack growth remains fairly well directed in spite of the stochastic nature of the crack growth process.