Comparison of the Young’s moduli of polymers measured from nanoindentation and bending experiments

Abstract

Spherical and conical nanoindentation experiments were performed for the same polymer specimens to compare Young’s moduli measured from the elastic loading and unloading curves, and bending experiments. Finite-element simulation was employed to ensure pure elastic deformation during spherical nanoindentation. The moduli measured from the elastic loading curves using Hertz’s contact law are very close to the bending moduli, because both measurements were conducted under the same elastic deformation. However, the moduli measured from the elastic unloading curves are up to 60% higher than the bending moduli owing to plastic deformation close to the sharp conical indenter tip.