When a load is applied to an assembly of particles and particle breakage occurs, the macroscopic behaviour of the assembly is greatly affected by changes in the micro-scale caused by breakage. In this project particle breakage is studied in 3D using x-ray tomography and simulating the process with the DEM.
The lack of an internal length scale parameter in classical continua leads to unrealistic numerical modelling of some phenomena related to the microstructure of the material such as size effect and strain localisation.
The objective of this research is to investigate the behavior of Dunkerque sand under undrained triaxial cyclic loading using the discrete element method (DEM).
From cement and ceramic pastes to paints and drilling fluids, dense suspensions of solid particles immersed in a liquid are ubiquitous in industries. Understanding the rheology of dense suspensions is important for explaining and predicting the multiphase flow behavior in traditional and innovative industrial processes. In this project, DEM simulations are employed to understand the rheology of suspensions containing different particles with different surface properties.
While the discrete element method (DEM) can provide particle-scale information to inform the design of particulate equipment, many industrial sectors are interested in large-scale modelling and scaling-up processes [1].
Particle shape has important effects on bulk materials as sandpiles and mixtures; temporal changes of the shape (e.g. due to surface abrasion) also have severe consequences in many industrial sectors. To represent irregular particles, a compact “irregularity function” can be stored for each particle which describes how the shape deviates from a bounding sphere. Abrasion can be studied by adopting irregularity functions which can change with time depending on contact force.
This project aims to create a generally applicable framework for transferring academic innovations in the modelling of particulate materials into industrial practice in the UK. The process of twin-screw granulation has been selected as an exemplar industrial process which is simulated across multiple scales using the coupled methods of population balance modelling and the discrete element method.
The Edinburgh part of the project focues on the multi-physics modelling of particle dynamics and sintering behaviour in selective laser sintering processes. This work is an integrated part of an EPSRC funded project to develop fundamental understanding of particle behavour in additive manufacturing, collaborating with the University of Exeter. This project proposes to investigate the way polymeric powders of different shapes and sizes flow, interact and sinter in the laser sintering process, through modelling and experimental validation. Laser sintering is part of the additive manufacturing technology, known for its benefits in industries where custom made products, lightweight and complex designs are required.
The Edinburgh part of the project focuses on multi-physics modelling of particle dynamics and suspension rheology in electrical discharge processes. This work is an integrated part of an EPSRC funded project to develop novel electrical discharge methods (EDM) for functional surface coating, collaborating with The University of Nottingham. This project aims to revolutionise the way industrial electrical discharge machining processes can be used. It will transform the process from a machining only technique to a method that is also capable of novel surface treatments at the same time.
We examine the rheology of granular dense suspensions using computer simulations with discreste particles and develop constitutive models for flow of such suspensions.
