Formability evaluation based on a constitutive model with stress rate direction dependency considering bifurcation modes

Abstract Accurately predicting the fractures that occur in materials during forming not only improves quality, but also reduces amount of material is discarded. Therefore, as a key technology for digital transformation to achieve carbon neutrality, it necessary improve accuracy analysis and establish an efficient method limits. Formability assessment typically performed using ductile fracture criteria or experimental limit diagrams (FLDs), which require prior testing. The authors have established evaluation based on three-dimensional local bifurcation theory versatile does destructive This can follow abrupt changes stress field, such localized necking, by flow rule takes into account directionality rate. In this study, proposed applied tensile testing square cup drawing analytically verify location onset time modes may lead fracture.