Modeling and computation of metal powder compaction processes

In this short communication the numerical treatment of a thermomechanical consistent finite strain viscoplasticity model for metal powder compaction is discussed. The convex single surface yield function evolves according to two evolution equations and remains convex under all loading conditions. The very challenging numerical treatment on local level for integrating the constitutive model requires particular globally convergent Newton-like method with inequality constraints so that a stable solution scheme results. This is embedded into a time-adaptive finite element program which makes use of diagonally-implicit Runge-Kutta methods combined with a Multilevel-Newton algorithm. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)