Evaluation of ductile fracture models for different metals in blanking

This study is focussed on the evaluation of ductile fracture methodologies, which are needed to predict product shapes in the blankingprocess. In an earlier publication [Goijaerts et al., J. Manuf. Sci. Eng., Trans. ASME 122 (2000) 476], two approaches were elaboratedusing local ductile fracture models. The first strategy incorporates the characterisation of a ductile fracture model in a blanking experiment.The second methodology is more favourable for industry. In this approach, instead of a complex and elaborate blanking experiment, atensile test is used to characterise a newly proposed criterion, which was shown to predict accurately the ductile fracture for differentloading conditions. In this paper, finite element simulations and experiments are performed on both tensile testing and blanking to evaluatethe validity! of both approaches with corresponding criteria for five different metals. In the blanking process, different clearances as well asdifferent cutting radii of the tools are considered. In conclusion, it can be stated that the first approach gives very good results close to, orwithin the experimental error for all five materials. The second approach, the more favourable one for industry, yields good results thatdeviate slightly more over the range of metals.