A robust identification protocol of flow curve adjusting parameters using uniaxial tensile curve

Abstract

Abstract. ArcelorMittal is constantly developing new steel grades to enable the automotive industry to offer safer, lighter, and more environmentally friendly vehicles. These new grades include advanced high-strength steels (AHSS) and Ultra High Strength steels (UHSS) having for some of them lower uniform elongation (UE) than conventional drawing steels. This particularity needs to be considered for an accurate formability prediction in sheet forming numerical simulations. One of these difficulties is the effect of the relatively low uniform elongation on the identification of the parameters of the isotropic hardening model. Various experimental tests can be used to reach the large plastic deformation (hydraulic bulge test, stack compression test, shear test, torsion test or plane strain compression test). The identification protocol of ArcelorMittal for hardening models is based solely on stress-strain curves determined in uniaxial tension. The Exp_S hardening law (TU experimental values before UE%, Swift extension above) was validated by comparison with the stress-strain curves obtained from measurements of experimental tests reaching large strains.