An improved analytical description of orthotropy in metallic sheets

The correct description of initial plastic anisotropy of metallic sheets plays a key role in modelling of sheet forming processes since prediction of material flow, residual stresses and springback as well as wrinkling and limiting strains are significantly affected by the phenomenological yield function applied in the analysis. In the last decades considerable improvement of anisotropic yield criteria has been achieved. Among these, the yield criterion proposed by Paraianu et al. [An improvement of the BBC2000 yield criterion. In: Proceedings of the ESAFORM 2003 Conference] is one of most promising plane stress yield criteria available for orthotropic sheet materials. This work aims to improve this yield criterion with respect to flexibility. The capabilities of the modified yield function will be demonstrated by applications to an anisotropic aluminium alloy sheet material.