A STUDY ON PROCESS IMPROVEMENTS OF MULTISTAGE DEEP-DRAWING BY THE FINITE-ELEMENT METHOD

Multi-stage deep-drawing processes, including normal drawing, reverse drawing, and redrawing, to shape the front shell of a master VAC for a n automobile have been analyzed sequentially by the use of the rigid-p lastic finite-element method, computational results on the punch/die l oads and thickness distributions being obtained. The thickness strains were compared with the results of experiments on current drawing proc esses, good agreement being found. Deep-drawing processes of the redes igned shell to improve the specific strength and stiffness were simula ted with the numerical method developed. By varying several process pa rameters, such as the blank size, the corner radii of the tools, and t he clearances, the simulation results showed improvements in reducing the forming loads. Also, forming defects were found during simulation and the appropriate blank size could be verified.