A device for studying elementary plasticity fluctuations in granular media

TL;DR

This paper introduces a specialized device for studying the fluctuations in plasticity that occur before fracture in granular media, using biaxial tests and optical measurement techniques.

Contribution

The paper presents a novel device and method for detecting discrete plasticity events in granular media, independent of strain rate effects.

Findings

Plasticity fluctuations depend solely on imposed strain.

The device can unambiguously detect discrete plasticity events.

Fluctuations are unaffected by strain rate.

Abstract

In this manuscript, we describe a scientific device specifically designed for the study of the plasticity fluctuations preceding the fracture of granular media. Biaxial tests on model granular media are performed using a commercial uniaxial loading system. Strain field fluctuations are measured using a method based on the interference of coherent light scattered by the sample. We show that such a device enables discrete plasticity events to be unambiguously evidenced. Moreover, those discrete plasticity fluctuations depend only on the imposed strain, and not on the strain rate.