Numerical Investigations on Cutting of Dual-Phase Sheet Steel with an Emphasis on Material Damage at the Cut Edge

With the help of an explicit finite element analysis, cutting of cold-rolled dual-phase steels for various tool clearances was studied. In the first part of the study, the influence of the element size in the shear zone of the sheet on the predicted cut edge geometry and punch force was assessed and the optimal simulation parameters were identified. In the second part, the fracture description was put into focus of the investigation. It is shown that the used mathematical description of the equivalent plastic strain at fracture as a function of the stress triaxiality does not yield accurate results for FEA-based prediction of the cut edge geometry. A need in a more accurate fracture characterisation and, possibly, a more advanced fracture description of dual-phase sheet steels and the directions of the future research are identified.