ASSESSMENT OF BEHAVIOUR OF SHEET METAL DURING HYDROFORMING.

Abstract

The behaviour of copper sheet during the bulge test is discussed in the light of formability which may adequately be described in terms of deformation and shape. In the present paper, the local shape of the deformed shell is interpreted through the concept of prolateness, which is derived from the principal curvatures and which describes their deviation from a reference sphere. The effects of two important process parameters on the bulge test, namely, the magnitude of the die shoulder radius and the amount of draw-in present during forming, are discussed.