Nanoscale fracture of tetrahedral amorphous carbon by molecular dynamics: Flaw size insensitivity

Qiang Lu, Nigel Marks, George C. Schatz, Ted Belytschko

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The fracture of tetrahedral amorphous carbon at the nanoscale was investigated with molecular dynamics simulations using the environment-dependent interatomic potential. It was found that the fracture strength of amorphous carbon nanospecimens is insensitive to initial cracks with diameters smaller than about 40 Å, i.e., the material exhibits flaw tolerance at the nanoscale. It was also found that amorphous carbon nanospecimens fracture very differently from diamond; (i) failure is gradual instead of catastrophic and (ii) it is accompanied with voidlike defect growth and coalescence. This fracture behavior appears to result from the structural disorder of amorphous carbon. In order to further explore the effect of crack size in materials with structural disorder, larger two-dimensional random network models were studied and found to also exhibit void growth during fracture and flaw tolerance.

Original languageEnglish
Article number014109
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume77
Issue number1
DOIs
Publication statusPublished - Jan 25 2008

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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