Inverse estimation approach for elastoplastic properties using the load-displacement curve and pile-up topography of a single Berkovich indentation

An approach for the inverse estimation of the elastoplastic properties from a single indentation with a Berkovich indenter was developed. The relationship between the load-displacement and stress-strain curves was derived based on the equivalent energy principle, while an approximate equation for pile-up height was determined using elastic and plastic limits. The approach proposed in this study estimates the yield stress and strain-hardening exponent from hardness and pile-up height obtained from a single indentation based on these fundamental equations. The coefficients in the equations were determined in a parametric study using finite element analyses. The accuracy of the inverse estimation technique was confirmed using aluminum alloy and stainless steel samples and reference tensile testing.