Production of individualised sheet metal parts using incremental shrinking

Shrinking is an incremental forming process and can be carried out using a driving machine, the so called "Kraftformer", to form sheet metal parts in different three-dimensional forms. This is traditionally performed by manual labour, so that cost-effective productions can't be reached for custom-made sheet metal parts. Hence, it is proposed to automate this forming process to reduce the quantity of manual work involved. A direct way to get possible production strategies is to simulate the forming process in a FEM-software environment. However, within such a FEM-simulation it can take up to one hour to finish just one forming step. On the other hand, an analytical modelling of the shrinking cannot be realized because of its complex procedures such as variation of contact conditions and material hardening. In this paper, the CAM concept will be presented, in which there are two necessary steps to obtain the production strategy to form a sheet metal part in a desired geometry: at first, a geometric forming model will be established to demonstrate the change in the 3D-forms of the sheet metal parts, as the contour of the metal blank is created by the flattening process; at second, based on the flattened metal blank and the geometrical model, the derivation of the production strategy will be carried out by the use of Genetic Algorithm.