Atomistics of crack propagation

Karl Sieradzki, G. J. Dienes, A. Paskin, B. Massoumzadeh

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

The molecular dynamic technique is used to investigate static and dynamic aspects of crack extension. The material chosen for this study was the 2D triangular solid with atoms interacting via the Johnson potential. The 2D Johnson solid was chosen for this study since a sharp crack in this material remains stable against dislocation emission up to the critical Griffith load. This behavior allows for a meaningful comparison between the simulation results and continuum energy theorems for crack extension by appropriately defining an effective modulus which accounts for sample size effects and the non-linear elastic behavior of the Johnson solid. The simulation results for the energetics of quasi-static crack extension are in very good agreement with continuum predictions. During quasi-static crack extension under constant load boundary conditions the ratio of the work done by the external loads to the increase in elastic strain energy is ~ 1.94 which is close to the continuum prediction of 2.00 for a linear elastic solid. Good agreement was also obtained between the simulation results for the critical stress and the predictions of the Griffith criterion. Normalized crack velocity-crack length curves are presented for a variety of sample sizes and a variety of loading conditions. The measured terminal velocity was independent of sample size and loading condition and was 0.25 of the longitudinal sound velocity. The method of loading has some influence on acceleration of the crack to the terminal velocity. The details of the energy balance during dynamic crack extension are presented for various sample sizes. For the largest sample examined the crack reaches terminal velocity well before any elastic wave reflections occur at the sample boundary. Simulation results are presented for the stress fields of moving cracks and these dynamic results are discussed in terms of the dynamic crack propagation theories of Mott, Eshelby, and Freund.

Original languageEnglish (US)
Pages (from-to)651-663
Number of pages13
JournalActa Metallurgica
Volume36
Issue number3
DOIs
StatePublished - 1988
Externally publishedYes

Fingerprint

Crack propagation
Cracks
Elastic waves
Acoustic wave velocity
Strain energy
Energy balance
Molecular dynamics
Boundary conditions
Atoms

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Sieradzki, K., Dienes, G. J., Paskin, A., & Massoumzadeh, B. (1988). Atomistics of crack propagation. Acta Metallurgica, 36(3), 651-663. https://doi.org/10.1016/0001-6160(88)90099-5

Atomistics of crack propagation. / Sieradzki, Karl; Dienes, G. J.; Paskin, A.; Massoumzadeh, B.

In: Acta Metallurgica, Vol. 36, No. 3, 1988, p. 651-663.

Research output: Contribution to journalArticle

Sieradzki, K, Dienes, GJ, Paskin, A & Massoumzadeh, B 1988, 'Atomistics of crack propagation', Acta Metallurgica, vol. 36, no. 3, pp. 651-663. https://doi.org/10.1016/0001-6160(88)90099-5
Sieradzki, Karl ; Dienes, G. J. ; Paskin, A. ; Massoumzadeh, B. / Atomistics of crack propagation. In: Acta Metallurgica. 1988 ; Vol. 36, No. 3. pp. 651-663.
@article{81440dbae3c34ea6afcc76270ffb33f8,
title = "Atomistics of crack propagation",
abstract = "The molecular dynamic technique is used to investigate static and dynamic aspects of crack extension. The material chosen for this study was the 2D triangular solid with atoms interacting via the Johnson potential. The 2D Johnson solid was chosen for this study since a sharp crack in this material remains stable against dislocation emission up to the critical Griffith load. This behavior allows for a meaningful comparison between the simulation results and continuum energy theorems for crack extension by appropriately defining an effective modulus which accounts for sample size effects and the non-linear elastic behavior of the Johnson solid. The simulation results for the energetics of quasi-static crack extension are in very good agreement with continuum predictions. During quasi-static crack extension under constant load boundary conditions the ratio of the work done by the external loads to the increase in elastic strain energy is ~ 1.94 which is close to the continuum prediction of 2.00 for a linear elastic solid. Good agreement was also obtained between the simulation results for the critical stress and the predictions of the Griffith criterion. Normalized crack velocity-crack length curves are presented for a variety of sample sizes and a variety of loading conditions. The measured terminal velocity was independent of sample size and loading condition and was 0.25 of the longitudinal sound velocity. The method of loading has some influence on acceleration of the crack to the terminal velocity. The details of the energy balance during dynamic crack extension are presented for various sample sizes. For the largest sample examined the crack reaches terminal velocity well before any elastic wave reflections occur at the sample boundary. Simulation results are presented for the stress fields of moving cracks and these dynamic results are discussed in terms of the dynamic crack propagation theories of Mott, Eshelby, and Freund.",
author = "Karl Sieradzki and Dienes, {G. J.} and A. Paskin and B. Massoumzadeh",
year = "1988",
doi = "10.1016/0001-6160(88)90099-5",
language = "English (US)",
volume = "36",
pages = "651--663",
journal = "Acta Materialia",
issn = "1359-6454",
publisher = "Elsevier Limited",
number = "3",

}

TY - JOUR

T1 - Atomistics of crack propagation

AU - Sieradzki, Karl

AU - Dienes, G. J.

AU - Paskin, A.

AU - Massoumzadeh, B.

PY - 1988

Y1 - 1988

N2 - The molecular dynamic technique is used to investigate static and dynamic aspects of crack extension. The material chosen for this study was the 2D triangular solid with atoms interacting via the Johnson potential. The 2D Johnson solid was chosen for this study since a sharp crack in this material remains stable against dislocation emission up to the critical Griffith load. This behavior allows for a meaningful comparison between the simulation results and continuum energy theorems for crack extension by appropriately defining an effective modulus which accounts for sample size effects and the non-linear elastic behavior of the Johnson solid. The simulation results for the energetics of quasi-static crack extension are in very good agreement with continuum predictions. During quasi-static crack extension under constant load boundary conditions the ratio of the work done by the external loads to the increase in elastic strain energy is ~ 1.94 which is close to the continuum prediction of 2.00 for a linear elastic solid. Good agreement was also obtained between the simulation results for the critical stress and the predictions of the Griffith criterion. Normalized crack velocity-crack length curves are presented for a variety of sample sizes and a variety of loading conditions. The measured terminal velocity was independent of sample size and loading condition and was 0.25 of the longitudinal sound velocity. The method of loading has some influence on acceleration of the crack to the terminal velocity. The details of the energy balance during dynamic crack extension are presented for various sample sizes. For the largest sample examined the crack reaches terminal velocity well before any elastic wave reflections occur at the sample boundary. Simulation results are presented for the stress fields of moving cracks and these dynamic results are discussed in terms of the dynamic crack propagation theories of Mott, Eshelby, and Freund.

AB - The molecular dynamic technique is used to investigate static and dynamic aspects of crack extension. The material chosen for this study was the 2D triangular solid with atoms interacting via the Johnson potential. The 2D Johnson solid was chosen for this study since a sharp crack in this material remains stable against dislocation emission up to the critical Griffith load. This behavior allows for a meaningful comparison between the simulation results and continuum energy theorems for crack extension by appropriately defining an effective modulus which accounts for sample size effects and the non-linear elastic behavior of the Johnson solid. The simulation results for the energetics of quasi-static crack extension are in very good agreement with continuum predictions. During quasi-static crack extension under constant load boundary conditions the ratio of the work done by the external loads to the increase in elastic strain energy is ~ 1.94 which is close to the continuum prediction of 2.00 for a linear elastic solid. Good agreement was also obtained between the simulation results for the critical stress and the predictions of the Griffith criterion. Normalized crack velocity-crack length curves are presented for a variety of sample sizes and a variety of loading conditions. The measured terminal velocity was independent of sample size and loading condition and was 0.25 of the longitudinal sound velocity. The method of loading has some influence on acceleration of the crack to the terminal velocity. The details of the energy balance during dynamic crack extension are presented for various sample sizes. For the largest sample examined the crack reaches terminal velocity well before any elastic wave reflections occur at the sample boundary. Simulation results are presented for the stress fields of moving cracks and these dynamic results are discussed in terms of the dynamic crack propagation theories of Mott, Eshelby, and Freund.

UR - http://www.scopus.com/inward/record.url?scp=0023983708&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023983708&partnerID=8YFLogxK

U2 - 10.1016/0001-6160(88)90099-5

DO - 10.1016/0001-6160(88)90099-5

M3 - Article

AN - SCOPUS:0023983708

VL - 36

SP - 651

EP - 663

JO - Acta Materialia

JF - Acta Materialia

SN - 1359-6454

IS - 3

ER -