  Nanoindentation is a powerful tool capable of providing fundamental insights
of material elastic and plastic response at the nanoscale. Alloys at nanoscale
are particularly interesting as the local heterogeneity and deformation
mechanism revealed by atomistic study offers a better way to understand
hardening mechanism to build a stronger material. In this work, nanoindentation
in Al-Cu alloys are studied using atomistic simulations to investigate the
effects of loading direction, alloying percentages of Cu via dislocation-driven
mechanisms. Also, a low-fidelity finite element (FE) model has been developed
for nanoindentation simulations where nanoscale materials properties are used
from atomistic simulations. Material properties, such as hardness and reduced
modulus, are computed from both the FE and MD simulations and then compared.
Considering the fundamental difference between these two numerical approaches,
the FE results obtained from the present study conform fairly with those from
MD simulations. This paves a way into finding material properties of alloys
with reduced simulation time and cost by using FE where high-fidelity results
are not required. The results have been presented as load-displacement
analysis, dislocation density, dislocation loops nucleation and propagation,
von-Mises stress distribution and surface imprints. The techniques adopted in
this paper to incorporate atomistic data into FE simulations can be further
extended for finding other mechanical and fracture properties for complex alloy
materials.
