Studies on Anisotropic Yield Characteristics and Press Formability of Metal Sheets : Investigation into Pure Stretch-Forming

Abstract

Based on Bassani yield criterion, a computer simulation of axi-symmetrical pure stretch-forming is attempted. A method for estimating the coefficient of friction necessary for the calculation is presented by extending Hill's method. The results calculated for four kinds of metal sheets are compared with the experimental data. The strain distribution and the fracture position are found to be sensitive to the shape of the yield locus, that is, anisotropic yielding, and it is concluded that the Bassani function is much more useful for the simulation than Hill's old criterion.