CLOSED-FORM SOLUTION FOR BULGING THROUGH ELLIPTICAL DIES

D. Banabic, T. Balan, D.-S. Comsa

Technical University of Cluj-Napoca, Romania

An analytical model is proposed for the elliptical bulging of sheet metals. The model uses the deformation theory and the classical Hill yield criterion. Some assumptions are made on the geometry of the part, in order to derive a closed-form solution. It can be applied to both strain-hardening and superplastic materials, for the analysis of the bulging tests through circular and elliptical dies. The results are shown to be in good agreement with the experiments and the finite element predictions. It is a fast analytical tool to estimate the forming pressure and the formability of the material using this specific mechanical test.

Keywords: hydrostatic bulging, elliptical bulging, superplastic material, analytical model