Deep-drawing through tractrix type dies

The investigation evaluates the effect of die profile on the drawing performance. Three die profiles, one near to the tractrix shape and the other two with larger radius of curvature, are considered. The materials tested include mild steel, stainless steel and soft aluminium. The drawing process is analysed using a numerical solution formulated earlier and the theoretical results on the punch load and the strain development are compared with the experimental results. Good correlation is obtained on the development of strains. The theoretical prediction of the punch load is reasonably good except for mild steel which is highly anisotropic. It is shown that by modifying the tractrix die profile, the punch load can be significantly reduced.