Intelligent sheet stamping process using segment blankholder modules

A sheet forming simulator with a finely segmented blank holder for stamping process of non-circular parts was developed to confirm the effect of variable distributed blank holding pressure (BHP). The BHP was controlled through an intelligent press control system. The same evaluation functions for fracture and wrinkling as ones in the previous work were adopted for fuzzy inference of incremental BHP. In this study, the simulator was applied to square-cup deep-drawing process, using 36 blank holder modules with 3 embedded hydraulic cylinders, that is, a total of 108 segment blank holding actuators were employed for controlling the material flow of blank into the die cavity. The blank holder unit can be flexibly constructed for forming process of an arbitrary shape because of a segment module structure. To facilitate the implementation of the simulator, the concept of virtual processing system was utilized. The BHP trajectories for each blank holder were obtained by the virtual database and finite element method (FEM)-assisted intelligent press control system based on the concept. Through the implementation of sequential BHP control according to the trajectory, the potential application of the simulator to non-circular parts was verified and discussed.