Prediction of the influence of yield locus on the limit strains in sheet metals

The paper presents a new approach to the Forming Limit Diagram (FLD) modeling. The yield criterion (1993), recently proposed by Hill, is used for the calculation of the limit strains in connection with the Swift’s instability condition for diffuse necking and by using the Marciniak–Kuczynski analysis. The influence of the ratio between uniaxial and biaxial yield stress (σu/σb), a, upon the FLD’s is presented.