Powder Compaction at Low and Medium Pressures: Consolidation Behavior of Nonlinear Powders Using a Mixed Discrete-Continuum Approach

Publication Reference: 
Author Last Name: 
A. M. Cuitino, S. Zheng
Report Type: 
ARR - Annual Report
Research Area: 
Particle Formation
Publication Year: 
Publication Month: 
United States

Executive Summary

This report is an integral part of an effort to develop a computational platform to virtually synthesize and test particle compacts based only on the bulk and sur- face properties of the particles prior to the consolidation process. This virtual man- ufacturing and testing facility (VMTF) includes die filling, compaction –particle rearrangement and particle deformation (elastic and inelastic)–, compact ejection and subsequent mechanical testing. The current simulation platform is based on a multiscale approach, which bridges systematically the micro and meso-scale. The VMTF will provide the ability to reproduce the behavior of current products but more importantly, it will enable the simulation of systems never yet manufactured, virtually screening the best manufacturing conditions and particle/granule proper- ties for a desired compact behavior or application. During this year we will con- tinue the development of the subsequent modules of die-ejection and mechanical testing.

The specific content of this report includes a numerical study of the mechan- ical behavior of systems composed by particles with different sizes and materials subjected to consolidation. The simulation methodology is based on a mixed dis- crete/continuum approach which allows to systematically bridge the microscale response (particle and inter-particle scale) with the mesoscale and macroscopic behavior (container/sample scale). The methodology is particularly suitable for describing the post-rearrangement regime where consolidation proceeds mostly by elastic and inelastic deformation. This formulation is able to provide quantitative estimates of the evolution of macroscopic variables, such as pressure and density, while following microlevel processes, such as local coordination number and load- ing paths. This methodology is applied to polydispersed systems composed by particles with different nonlinear properties. The predictions are in general agree- ment with the experimental data during both loading and unloading cycle.