Skip to main content

Creating Granular Materials Experts by Developing Experimental Calibrations for Computational Methods

Periodic Reporting for period 1 - CALIPER (Creating Granular Materials Experts by Developing Experimental Calibrations for Computational Methods)

Reporting period: 2019-09-01 to 2021-08-31

Granular materials such as sand, salt grains and coffee beans are everywhere. Predicting how granular materials flow and deform is obviously important for a wide range of sectors, yet still a highly challenging task. Computational methods to assist in handling granular materials have greatly improved in the past decades. However, these computational methods need more and more experimental calibration. Current calibration technology is completely insufficient to provide the required information to calibrate computational methods. CALIPER will train a cohort of experimental and computational experts by letting them develop and use innovative granular calibration technologies for industrial and academic purposes. The calibration methodologies will be based primarily on three dimensional imaging methods and advanced mechanical characterization techniques. CALIPER will so provide Europe with new knowledge and a unique team of professionals that will enhance the academic and industrial innovation capacity in a wide range of sectors for years to come.
In the first part of the CALIPER project, we have already developed several key innovations; we have so far published seven peer reviewed articles, five peer reviewed conference proceedings and completed fourteen conference presentations. We have for example studied granular flows in silos and hoppers, revealing new important couplings between the frictional and elastic behavior of granular materials. We have organized training schools for the students working in CALIPER, and are collecting large amounts of experimental data on the mechanical behavior of granular materials. Key development here is also the generation of a library of standardized particles with which we do experiments in multiple testing devices.
We have advanced calibration methods for granular materials to better characterize these materials both on their mechanical behavior and their microstructural evolution. We have advanced several numerical methods to better simulate soft particles flows, and particle flows of anisometric grains. In particular, we have been able to image the swelling of soft, deformable, anisometric couscous particles in 3D with both X-ray tomography and neutron tomography, providing the highest detail so far of a granular process that involves soft, sticky particles. We have developed novel discrete element method code to simulate the continuous and oscillatory flow behavior of deformable particles, the interactions among them and their coarse-grained mechanical response. These developments will allow us in the remainder of the project to publish data on the mechanical behavior of both model, standardized and industrially relevant grains. Training material developed in this project will find its way to open access repositories as well.
Lentils rotate in a packing that is compressed