Development of Shear Bands in Sheet Bending of Dual-Phase Steel

To further improve the performance of high-strength dual-phase steel, it is necessary to understand ductile fracture in dual-phase steel deeply. We have lately observed the formation of shear bands occurring prior to void formation, which have been considered the critical damage, during the sheet bending. In this study, the development of shear bands in sheet bending of dual-phase steel was numerically investigated. A zooming analysis that reflects microstructural information reproduced the development of shear bands experimentally observed. Additionally, a parametric study where the stress-strain curves of the soft phase was varied suggested that the width and number of shear bands are strongly influenced by the strength difference between the two phases in both the early and later stages of bending deformation.