A study on the constitutive equation effects in the fracture initiation of AA5450 sheets

Abstract

Determination of the fracture initiation in the sheet metal forming applications can be achieved successfully using ductile fracture criteria (DFCs) and finite element codes together. In this study three different uncoupled, energy based ductile fracture criteria have been employed to predict the onset of the fracture in the AA5450 aluminum alloy sheets. Also, two different constitutive models namely, isotropic von-Mises and anisotropic Hill, have been implemented to the finite element code ABAQUS through VUMAT subroutine to investigate the effect of constitutive equations on the applicability of the utilized DFCs. It was shown that the constitutive model has significant influence on the estimation of the time and place of the fracture initiation in the sheets.