Quasicontinuum simulation of nanoindentation of nickel film
F. L. Zeng and Y. Sun
Acta Mechanica Solida Sinica, 19, 283-288 (2006).

ABSTRACT
A large-scale atom simulation of nanoindentation into a thin nickel film using
the quasicontinuum method was performed. The initial stages of the plasticity
deformation of nickel were studied. Several useful results were obtained as
follows: (1) The response of the load versus indentation depth - on the load
versus indentation depth curve, besides the straight parts corresponding to the
elastic property of nickel, the sudden drop of the load occurred several times;
(2) The phenomena of dislocation nucleation - the dislocation nucleation took
place when the load descended, which makes it clear that dislocation nucleation
causes the drop of the load; (3) The mechanism of the dislocation emission - the
Peierls-Nabarro dislocation model and a powerful criterion were used to analyze
the dislocation emission. And the computational value was in good agreement with
the predict value; (4) The density of geometrically necessary dislocations. A
simple model was used to obtain the density of geometrically necessary
dislocations beneath the indenter. Furthermore, the influence of the boundary
conditions on the simulation results was discussed.