Third M.I.T. Conference on Computational Fluid and Solid Mechanics June 14–17, 2005  

A three-invariant hardening cap plasticity for computational modeling of the powder compaction process

A.R. Khoeia,*, A.R. Azamib
aDepartment of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, USA bDepartment of Civil Engineering and Engineering Mechanics, McMaster University, Hamilton, Ontario L8S 4L7, Canada

  Full Text
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.

Keywords:  Powder compaction; Three-invariant plasticity; Isotropic hardening; Cap model

* Corresponding author. E-mail: