Heterogeneous tensile test on elastoplastic metallic sheets: Comparison between FEM simulations and full-field strain measurements

The aim of this work is to propose a non-standard tensile test suitable for the identification of material parameters using full-field strain measurements and finite element analysis. The shape of the sample to be used in this new test must verify three criteria: (i) large heterogeneity of the strain in the gauge area, (ii) large strain-paths diversity and (iii) a good sensitivity of the strain field to the material parameters. After identifying the mechanical parameters of a dual-phase steel sheet using σσ–εε and rr–αα curves, samples of different shapes were studied in order to choose the one that presents the best compromise between the three criteria. The comparison between simulated and measured fields shows a qualitative accordance. Taking into account the difference between these fields in the expression of the cost-function to minimize is expected to improve the quality of the identified material parameters.