Amorphous silica exhibits a complex mechanical response. The elastic regime is highly nonlinear while plastic flow does not conserve volume, resulting in densification. As a result, the quantification of a reliable constitutive equation is a difficult task. We have assessed the potential of micropillar compression testing for the investigation of the micro-mechanical properties of amorphous silica. We have calculated the response of amorphous silica micropillars as predicted by finite element analysis. The results were compared to preliminary micro-compression tests. In the calculations, an advanced constitutive law including plastic response, densification, and strain hardening was used. Special attention was paid to the evaluation of the impact of substrate compliance, pillar misalignment, and friction conditions. We find that the amorphous silica is much more amenable that some metals to micro-compression experiments due to a comparatively high ratio between yield stress and elastic modulus. The simulations are found to be very consistent with the experimental results. However, full agreement cannot be obtained without allowance for the nonlinear response of amorphous silica in the elastic regime.
