Tool design is carried out for a multi-stage deep drawing and ironing process of a rectangular cup with the large aspect ratio
using the result of the finite element analysis. The analysis incorporates three-dimensional continuum elements for an elasto-plastic
finite element method with the explicit time integration scheme using LS-DYNA3D. The analysis simulates the five-stage deep
drawing and ironing process with the thickness control of the cup wall. Simulation is performed in order to investigate the failure
by tearing during the forming process at the initial state of tool design. The analysis reveals that the difference of the drawing ratio
within the cross section induces non-uniform metal flow which causes severe local extension. The irregular contact condition
between the blank and the die also induces non-uniform metal flow which causes local wrinkling. This paper identifies such
unfavorable mechanism in the rectangular cup drawing with ironing and proposes a new tool design with the guideline for modification
in the design of the process and the sequential tool shape. The finite element analysis result with the improved tool design
confirms that the proposed design not only reduces the possibility of failure but also improves the quality of a deep-drawn product.
The numerical result shows fair coincidence with the experimental result.