The Development of a Knowledge Based Cad System for Press Die Design

A decision-making framework to aid in component design, assessment of forming severity and development of preliminary die designs is being developed for automotive stampings. The automotive component design is assessed for its manufacturing feasibility by applying formability guidelines, incorporated as design rules in the knowledge based expert system (KBES). The formability guidelines were derived from material properties, deformation mechanics, finite element models and parametric studies and simple heuristics. Preliminary die designs (contacting surfaces) are developed by the KBES from heuristic design rules. The closure of the binder is modelled using LS- DYNA3D to predict the formed blank shape. The suitability of the deformed blank shape, to subsequent deformation by the punch, is evaluated by the KBES using a geometric punch/blank/die contact simulation. A strong synergy between the KBES and the FE-models is apparent. The FE-models supply design rules from parametric studies of idealized geometries for application early in the concept design phase. The KBES is used to develop preliminary die geometries of real components for further FE-analysis and refinement.