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 blanking process. In an earlier publication [Goijaerts et al., J. Manuf. Sci. Eng., Trans. ASME 122 (2000) 476], two approaches were elaborated using local ductile fracture m odels. The first strategy incorporates the characterisation of a ductile fr acture model in a blanking experiment. The second methodology is more favou rable for industry. In this approach, instead of a complex and elaborate bl anking experiment, a tensile test is used to characterise a newly proposed criterion, which was shown to predict accurately the ductile fracture for d ifferent loading conditions. In this paper, finite element simulations and experiments are performed on both tensile testing and blanking to evaluate the validity of both approaches with corresponding criteria for five differ ent metals. In the blanking process, different clearances as well as differ ent cutting radii of the tools are considered. In conclusion, it can be sta ted that the first approach gives very good results close to? or within the :experimental error for all five materials. The second approach, the more f avourable one for industry, yields good results that deviate slightly more over the range of metals. (C) 2001 Published by Elsevier Science B.V.