Sharp indentation stress fields in fused silica: Finite element analysis and Yoffe analytic model

Abstract

AbstractThe closed‐form Yoffe analytic model (1982), which superimposes two linear‐elastic stress fields, was developed as a first approximation to quantify the mechanical response of silicate glasses to sharp indentation. However, a detailed study with both experimental validation and numerical verification has yet to be published. This paper presents such a study, wherein experimental observation of crack systems in fused silica and numerical results from finite element analysis (FEA) are used to demonstrate the limitations of this analytic superimposition model. Specifically, analytic stress fields deviate from FEA numerical results and are inconsistent with several commonly observed crack systems. In contrast, FEA generated stress fields are entirely consistent with experimentally observed crack systems. Upon further investigation, it was found that the analytic model, with one tunable parameter, could not be adjusted to correlate with FEA and experimental evidence.