Extracting plastic properties from in-plane displacement data of spherical indentation imprint

Abstract This study proposes a method for evaluating elastic limit and strain hardening exponent by a single spherical indentation test. The method extracts the plastic properties from radial displacement fields and vertical profile of a residual imprint. Based on finite element (FE) and regression analyses, an evaluation algorithm is developed by relating the imprint data with plastic properties. Digital image correlation (DIC) method is used for measurements of the radial displacement fields. The errors of the properties determined with our method were less than 12 % for elastic limit stress, 0.6 for strain hardening exponent compared with those from tensile tests. The sensitivity of the inverse analysis algorithm is also shown to be acceptable.