Application of an ALE formulation for density-dependent hyperelastic-plastic models to the simulation of powder compaction processes

Abstract

Different quasi-static cold compaction processes of powders have been simulated with a density-dependent plastic model. The model is formulated within the framework of isotropic finite strain multiplicative hyperelastoplasticity. An elliptic plastic model expressed in terms of the Kirchhoff stresses and the relative density models the transition between the loose powder and the compacted sample. The Coulomb dry friction model is used to capture friction effects at die-powder contact. Excessive distortion of Lagrangian meshes due to large mass fluxes is usual in powder compaction problems. Because of this, an Arbitrary Lagrangian-Eulerian (ALE) formulation is used here. The present results illustrate that this approach allows simulating highly demanding powder compaction processes without mesh distortion and spurious oscillations in the results. Moreover, it is shown that the mass conservation principle is verified with a low relative error.