Investigation of Scar Formation in Fine Blanking Processes and their Prediction in 3D ALE Simulations

Abstract

Scar formation in fine blanking was investigated by means of a particularly developed fine blanking tool and experimental evidence about significant the process parameters chamfer size of the blanking tools, V-Ring usage and clearance is given. Furthermore, a special purpose Finite Element code using the Arbitrary-Lagrange-Eulerian method with a process specific mesh generation is demonstrated and used for the determination of relevant parameters for prediction crack formation in 3D fine blanking simulations. The simulations shown, that a commonly used description of fracture strain as a function of stress and deformation state is not sufficient. In order to simulate scar occurrence on the blanking surface, the significant increase of fracture strain due to temperature rise because of plastic heat generation has to be taken into account. A possible way of measuring the temperature effect was shown in torsion tests at different initial temperature levels.