Numerical simulation of the nanoindentation experiment: sensitivity analysis of the experimental parameters

The use of certain metallic materials in micro-mechanical systems applications is promising for chirurgical applications because of their bio-compatibility and interesting mechanical and wear properties compared to the widely used silicon. The reliability of miniaturized components, the building blocks of such systems depends largely upon the reliability of the techniques applied to characterize the materials, in relation with numerical simulations.

Nanoindentation is the method adapted to investigate the local mechanical properties of materials at the nanoscale. The inter-disciplinary nature of such an experiment makes the interpretation of the results difficult. The goal of the research is the use of a relatively simple but flexible computational tool for the simulation of the nanoindentation experiment in order to better understand the physics and the mechanics involved. A finite element code therefore has been developed and used to solve the simulation problem with all the non-linearities involved (finite deformations, plasticity, contact evolution), including isotropic plastic behavior with hardening and an accurate computational contact mechanics feature using the augmented Lagrangian scheme.

These tools allow to investigate the most significant sources of dispersion in nanoindentation experiments and their influence. This analysis helps to fix the range of given experimental parameters for which the sensitivity of experimental results is important.

The numerical simulation tool allows a parametric study to quantify the effects of some of these experimental conditions, such as the tip geometry and the surface roughness.