Granular media: experimental

analysis of the behaviour


 

 

The purpose of this lab course is to give Master students the opportunity to discover high-tech tools and up-to-date methods that are used to study the complex mechanical processes involved in the deformation of granular materials.

The students manipulate model granular materials and carry out experiments on laboratory equipments specifically designed to analyse their behaviour under controlled stress / strain conditions. The proposed approach, coupling experiments and numerical analysis, enables the participants to understand how the medium scale behaviour of such materials is driven by mechanisms occurring at the micro-scale (grain, finite element) and how to relate both scales through combining discrete and continuous methods.

Prerequisite

This lab-course is well suited to M1 and M2 students having a background in continuum mechanics, solid mechanics or particle mechanics.

Description of the lab-course

2D target tracking for the measurement of deformation in a model granular material

4 hrs session

The granular material is an assembly of rods (Schneebeli rods) confined by the experimental shear device 1g2e.

With 1g2e device, we apply at the boundaries of the assembly of rods, kinematics or stresses such that we can perform simple shear test or biaxial compression.

Various gauges (forces and displacement) are screened during the test. Hence, we obtain the relationship sigma = f(epsilon). Because the sample is 2D, grains kinematics can be assessed. For that purpose, we use a 80 MPixels camera (PhaseOne) and a DIC software (Digital Image Correlation) to assess the full kinematics of grains.

In this lab course, the mechanical behavior of 2D granular is introduced. Basics of scientific shootings are also presented.

Modelling granular material using the discrete element method

4 hrs session

Discrete Element Method (DEM) is used to simulate the mechanical behaviour of granular materials.

In this lab course, we model the behaviour of a numerical assembly of 2D grains generated from the assembly tests in the lab-course “1g2e”. We focus on the numerical parameters that have to be chosen to achieve relevant modelings. The results of the simulation are analyzed and compared to those measured on 1g2e experiments. A focus is made on observations at the micro-scale.


Location

This lab-course is hosted in the Eiffel Building of the laboratory 3SR located at 1301 rue de la piscine on the camus