Macroscopic and Microscopic Investigation on the History Dependence of the Mechanical Behaviour of Powders

TL;DR

This study compares experiments and simulations to understand how the history of precompaction affects the mechanical behavior of cohesive powders, revealing the importance of multiple characteristic lengths.

Contribution

It introduces a combined experimental and simulation approach to analyze history dependence in powder mechanics, highlighting the need for multiple characteristic lengths.

Findings

Precompaction history influences powder behavior.

Two different powders show similar history effects.

At least two characteristic lengths are needed to describe behavior.

Abstract

As an example for history dependent mechanical behaviour of cohesive powders experiments and computer simulations of uniaxial consolidation are compared. Some samples were precompacted transversally to the consolidation direction and hence had a different history. The experiments were done with two carbonyl iron powders, for which the average particle diameters differed by a factor of ca. 2. Whereas the particle diameter was the only characteristic length in the simulations, the evaluation of the experimental data indicates that at least a second characteristic length must be present.