Mechanical characterization of the elastoplastic response of a C11000-H2 copper sheet

Abstract

This work presents an elastoplastic characterization of a rolled C11000-H2 99.90% purecopper sheet considering the orthotropic non-associated Hill-48 criterion together with a modifiedVoce hardening law. One of the main features of this material is the necking formation at smallstrains levels causing the early development of non-homogeneous stress and strain patternsin the tested samples. Due to this fact, a robust inverse calibration approach, based on anexperimental–analytical–numerical iterative predictor–corrector methodology, is proposed to obtainthe constitutive material parameters. This fitting procedure, which uses tensile test measurementswhere the strains are obtained via digital image correlation (DIC), consists of three steps aimed at,respectively, determining (a) the parameters of the hardening model, (b) a first prediction of theHill-48 parameters based on the Lankford coefficients and, (c) corrected parameters of the yield andflow potential functions that minimize the experimental–numerical error of the material response.Finally, this study shows that the mechanical characterization carried out in this context is capable ofadequately predicting the behavior of the material in the bulge test.