Calibration of a strain path change model for a dual phase steel

Abstract

Dual phase steels are largely used to form automotive structural parts by deep drawing involving complex loading paths, which influence the material mechanical behavior and formability, as well as subsequent service life. The aim of this paper is to investigate the calibration of a strain path change model from an experimental database involving simple shear tests. The enhanced Homogeneous Anisotropic Hardening (e-HAH) is an advanced constitutive model that can take account of the strain path change influence on the material behavior by using a stress-based indicator. The performance of such a model depends highly on the material parameter identification and the experimental database. The mechanical behavior of a dual phase steel DP600 is first characterized under different linear strain paths, uniaxial and biaxial tension and simple shear, in order to quantify the initial anisotropy. Then, the influence of strain path changes on the material behavior is investigated during sequences involving simple shear, uniaxial tension and compression. Finally, the parameters of e-HAH model are identified and the influence of the experimental database on the optimised parameters is highlighted with the use of different strain paths and different strain ranges.