Highly strained mixtures of bidimensional soft and rigid grains: an experimental approach from the local scale

Jonathan Barés,Manuel Cárdenas-Barrantes,David Cantor,Mathieu Renouf,Émilien Azéma

doi:10.1051/epjconf/202124905004

Abstract

Granular systems are not always homogeneous and can be composed of grains with very diﬀerent mechanical properties. To improve our understanding of the behavior of real granular systems, in this experimental study, we compress 2D bidisperse systems made of both soft and rigid grains. By means of a recently developed experimental set-up, from the measurement of the displacementfield we can follow all the mechanical observables of this granular medium from the inside of each particle up-to the whole system scale. We are able to detect the jamming transition from these observables and study their evolution deep in the jammed state for packing fractions as high as 0.915. We show the uniqueness of the behavior of such a system, in which way it is similar to purely soft or rigid systems and how it is diﬀerent from them. This study constitutes thefirst step toward a better understanding of mechanical behavior of granular materials that are polydisperse in terms of grain rheology.

Highlights

1 Introduction we extend this method to the so called case of mixtures of Loaded granular materials made of highly deformable particles are ubiquitous in nature and industry from cell monolayer growth [1, 2] to foam and emulsion compression [3,4,5] and even metal or plastic powder sintering [6, 7]
It is applied here to the case of a mixed granular media made of soft squeezable particles and rigid ones
We have shown that our system crosses the jamming transition for a packing fraction and a coordination value close from what has been observed in the case of purely rigid systems

Summary

Introduction

1 Introduction we extend this method to the so called case of mixtures of Loaded granular materials made of highly deformable particles are ubiquitous in nature and industry from cell monolayer growth [1, 2] to foam and emulsion compression [3,4,5] and even metal or plastic powder sintering [6, 7]. Because of impurities or for technical and recycling purposes, rigid, undeformable particles are mixed among soft ones [8, 9]. For soft particles a DIC algorithm aimed for large deformations already presented in [18] is used to obtain the displacement field (u) inside each particle.

Results

Conclusion