Numerical Investigation on Formability of Ellipse Deep Drawing by Sheet Hydroforming

Abstract

This paper presents the numerical investigation on the formability of the sheet hydroforming by a finite element method. The finite element method code for sheet hydroforming simulation was developed based on the static‐explicit finite‐element method code STAMP3D. Experiments and Simulations of ellipse deep drawings were performed. The simulated thickness strain distribution which has two local thinnings at the punch shoulder and at the upper part of the side wall well agreed with the experimental one, thus demonstrating the validity of the developed code. Moreover, the effects of the friction increasing effect which is one of the main features in the sheet hydroforming on the formability were examined by comparing the results between the simulations with the friction coefficient μ=0 and those with μ=0.15. When μ=0 was employed, the local thinning at the upper part of the side wall disappeared. This showed that the occurring the two local thinnings in the sheet hydroforming was originated in the friction increasing effect.