Publications
A novel approach to study dislocation density tensors and lattice-rotation patterns in atomistic simulations
C. Begau, J. Hua, A. Hartmaier.
Journal of the Mechanics and Physics of Solids, 60, 711-722, (2012)
Abstract
Crystal plasticity caused by the nucleation and interaction of dislocations is an
important aspect in crystal deformation. Recent nanoindentation experiments in single
crystals of copper or aluminum revealed large deviations in the lattice rotation and an
inhomogeneous distribution of the dislocation density in the plastic zone under the
indenter tip. Molecular dynamics simulations offer the possibility to study the origin of
these phenomena on an atomistic scale, but require sophisticated analysis routines in
order to deal with the massive amount of generated data. Here a new efficient approach
to analyze atomistic data on the fly during the simulation is introduced. This approach
allows us to identify the dislocation network including Burgers vectors on the timescale
of picoseconds and below. This data does not only reveal the evolution of dislocation
structures, but it offers the possibility to quantify local dislocation density tensors
calculated on an atomic level. The numerical results are compared with experimental
data from the literature. The presented approach provides useful insight into the active
deformation mechanisms during plastic deformation that will help us to bridge
simulations on atomic scales and continuum descriptions.
Keyword(s): Dislocations;Indentation and hardness;Numerical algorithms
DOI: doi:10.1016/j.jmps.2011.12.005
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