Numerical analysis of defects in deep drawing of elliptical head

Deep drawing of elliptical head is theoretically analyzed and simulated on the generation of the typical defects as wrinkling and tearing. This study shows that the coaction of radial tension stress σ_r and tangential compression stress σ_θmakes materials drawn in the die successfully. Wrinkling occurs at the middle of the drawing process and tearing near the end, when σ_r and σ _θ is inconsistent. Small blank holder force (BHF) or good lubrication (μ) will reduce σ_r, and so, they will lead to inner-wrinkling; on the contrary, too large σr will result in tearing. Large radii of the die (R_D) and die-punch clearance (δ) increase the size of the suspended section, which weakens the wrinkle resistance of the blank, while too small values of them will make materials unable to be drawn in the die, thus tearing occurs. Finally, the values of BHF as 7 MPa, μ as 0.15, R_D as 30 mm and δ as 6.0 mm are proved to be the suitable values for deep drawing of the elliptical head.