INVESTIGADORES
BRINGA Eduardo Marcial
artículos
Título:
Simulations of copper single crystals subjected to rapid shear
Autor/es:
A. HIGGINBOTHAM; E.M. BRINGA
Revista:
JOURNAL OF APPLIED PHYSICS
Editorial:
AMER INST PHYSICS
Referencias:
Lugar: New York; Año: 2011 vol. 109 p. 63530 - 63536
ISSN:
0021-8979
Resumen:
We report on nonequilibrium molecular dynamics simulations of single
crystals of copper experiencing rapid shear strain. A model system, with
periodic boundary conditions, which includes a single dislocation
dipole is subjected to a total shear strain of close to 10% on
time-scales ranging from the instantaneous to 50 ps. When the system is
strained on a time-scale short compared with a phonon period, the
initial total applied shear is purely elastic, and the eventual
temperature rise in the system due to the subsequent plastic work can be
determined from the initial elastic strain energy. The rate at which
this plastic work occurs, and heat is generated, depends on the
dislocation velocity, which itself is a function of shear stress. A
determination of the stress-dependence of the dislocation velocity
allows us to construct a simple analytic model for the temperature rise
in the system as a function of strain rate, and this model is found to
be in good agreement with the simulations. For the effective
dislocation density within the simulations, 7.8×1011cm−2,
we find that applying the total shear strain on time-scales of a few
tens of picoseconds greatly reduces the final temperature. We discuss
these results in the context of the growing interest in producing high
pressure, solid-state matter, by quasi-isentropic (rather than shock)
compression.