The CALIPER research program focuses on three major challenges in granular materials-related calibration and simulations: deformable grains, irregular grains and cohesive grains. In each of these subject areas we move beyond the “spherical cow” paradigm that has understandably dominated the granular field for a long time. In each of these subjects, our envisioned approach will consists of developing experimental imaging and mechanical testing methods suitable for resolving the physical mechanisms at play, while extracting calibration information from such methods to develop numerical methods for the granular mechanisms/systems involved.

Of key importance is to provide a deep fundamental understanding of the dominant physical mechanisms that contribute to the mechanics of deformable, irregular or cohesive grain packings. The developed calibration methods and appropriate computational schemes will, therefore, be applied on both industrially relevant materials and on appropriately simplified granular model systems. The outcomes are then a generic academic understanding of granular materials, but also application specific knowledge that can support the development of e.g. digital twins for “industrial plant simulators”.
Output
Our peer reviewed scientific output so far can be found in the list below:
- Transparent experiments: releasing data from mechanical tests… and a WCCM-ECCOMAS presentation
- Particle flow rate in silos with rotational shear
- Flow in an hourglass: particle stiffness and friction matter
- Intermittent flow and transient congestion of soft spheres passing narrow orifices
- Silo discharge of mixtures of soft and rigid grains
- Evolution of fabric anisotropy of granular soils: x-ray tomography measurements and theoretical modelling
- Continuously heated granular gas of elongated particles
- Contact evolution in granular materials with inherently anisotropic fabric
- X-ray tomographies of a water-sensitive granular material (couscous) exposed to high relative humidity: an experimental study
- Discharge of elongated grains from silo with rotating bottom
- Modeling Combined Fabric Evolution in an Anisometric Granular Material Driven by Particle-Scale X-Ray Measurements
- Discrete element modeling of strongly deformed particles in dense shear flows
- Self-diffusion of spherocylindrical particles flowing under non-uniform shear rate
- Creep control in soft particle packings
- The effect of high relative humidity on a network of water-sensitive particles (couscous) as revealed by in situ X-ray tomography
- Secondary flow in ensembles of nonconvex granular particles under shear
- Fabric evolution and strain localisation in inherently anisotropic specimens of anisometric particles (lentils) under triaxial compression
Caliper students have already presented at several conferences:
- American Physical Society March Meeting 2021
- Annual European Rheology Conference 2021
- ICTAM 2021
- DPG 2021
- Powders & Grains 2021
- Particles 2021
- Physics@Veldhoven 2022
- American Physical Society March Meeting 2022
- Annual European Rheology Conference 2022
- ESMC 2022
- SoftComp 2022
- ICTMS 2022
- Gordon Research Seminar/Conference 2022
- CHOPS 2022
- IUTAM 2022
- WCPT 2022
- DPG 2022