Discrete ductile fracture modelling for the metal blanking process

Design and realisation of a metal blanking process in current industrial practice are mainly based on empirical knowledge. For more sophisticated applications, involving high accuracy geometry specifications, or nonstandard materials and product shapes, this empirical approach often fails. This paper presents a set of interrelated numerical techniques resulting in a finite element model of the metal blanking process, focusing on the prediction of the shape of the cut edge of a blanked product. The large, localised deformations are handled by an Operator Split Arbitrary Lagrange Euler (OS-ALE) method supplemented by full remeshing. Transport of the state variables between subsequent meshes for the OS-ALE and remeshing methods is accomplished by the Discontinous Galerkin (DG) method and an interpolation procedure, respectively. Ductile fracture is incorporated using a discrete cracking approach, which is shown to generate mesh independent results.