ABSTRACT
In this paper, a three-invariant cap plasticity is developed for description of powder behavior under cold compaction process. The constitutive elasto-plastic matrix and its components are derived as the nonlinear functions of powder relative density. It is shown how the proposed model could generate the elliptical yield surface, double-surface cap plasticity, and the irregular hexagonal pyramid of the Mohr-Coulomb and cone-cap yield surface, as special cases. The single-cap plasticity is performed within the framework of large finite element deformation, in order to predict the non-uniform relative density distribution during powder die pressing. Finally, the numerical schemes are examined for efficiency in the modeling of an automotive component.