Experimental and numerical determination of forming limit diagram for 1010 steel sheet: a crystal plasticity approach

摘要

This paper focuses on the study of 1010 steel sheet formability from a crystal plasticity viewpoint. The study is divided into experimental and numerical parts. In the experimental section, the initial texture of the sheet is measured through x-ray diffraction technique. Also, the stress-strain behaviour and FLD of the material are determined by performing simple tension and hemi-spherical punch tests, respectively. The presented experimental data provides the complete set of required input data for crystal plasticity simulation of 1010 steel sheet behaviour. In the numerical section, the rate dependent crystal plasticity model along with the power law hardening are employed in a user material (UMAT) subroutine to model the material behaviour. In order to determine FLD, second-order derivative of sheet thickness variations with respect to time is used as necking criterion. It is observed that the predicted FLD is in good agreement with the experimental curve. Finally, some points to further improve FLD prediction accuracy are remarked.