Identification of sheet metal hardening for large strains with an in-plane biaxial tensile test and a dedicated cross specimen

•Experimental in-plane biaxial tensile tests.•Identification of sheet metal hardening under large strains.•A dedicated flat cruciform specimen shape for large strains has been proposed.•Considering three different yield criteria, Voce's hardening law has been identified.

In this work, an in-plane biaxial tensile test of cruciform specimen is performed to identify the hardening behaviour of metallic sheets under large strains. Firstly, an optimal shape of the specimen is suggested. Then, a biaxial tensile test is carried out for an aluminium alloy AA5086. Experimental forces on the two axes of the specimen are measured during the test and strains in the central area of the specimen are post-treated by means of Digital Image Correlation (DIC) technique. Finally, by considering different yield criteria, the associated hardening laws are identified thanks to an inverse procedure based on a Finite Element (FE) modelling of the biaxial tensile test and on the experimental data mentioned above. The identified biaxial flow curves are then compared with the ones from the classical uniaxial tensile test.