We have performed a systematic molecular dynamics study of the competition between crack growth and dislocation emission from a crack tip. Two types of boundary conditions are adopted: either planar extension or boundary displacements according to the anisotropic mode-I asymptotic continuum solution. The effects of temperature, loading rate, crystal orientation, sharpness of the crack tip, atomic potential, and system size are investigated. Depending on the crystal orientation, dislocation nucleation can be driven either by the strain or by concerted fluctuations at the crack tip. In the latter case, crystal orientation and temperature have the largest influence on the process of dislocation nucleation.
|Pagina's (van-tot)||art. - 054111|
|Tijdschrift||Physical Review. B: Condensed Matter and Materials Physics|
|Nummer van het tijdschrift||5|
|Status||Published - feb.-2005|