A dual-mesh strategy for the 3d simulation of fineblanking processes

Fineblanking technology is used to produce blanked metal components which show outstanding surface quality and part flatness. The defining characteristics of the process are, besides the use of a counter punch and a V-Ring, the tiny die clearance and a rounded cutting edge. The 3D FE simulation of the process proves to be thus very challenging. This is mainly because in comparison to the part dimensions (which are of the order of 10mm) a very small mesh size needs to be chosen on the cutting edge (~0.01mm), which leads to a very big number of elements and also tiny time steps. This paper aims to show a solution to the problem using the Arbitrary Lagrangian Eulerian FE formulation, applied on two different levels of refinement. First a relatively coarse mesh (element size of about 0.1mm around the cutting edge) is applied to solve the full size 3D problem. The flow information is subsequently used on a much finer mesh (size ~0.005) defined around a small region on the cutting line to accurately compute the stress-strain distribution around the radii. © Springer/ESAFORM 2009.