Discrete Element Method (DEM) simulations at the length scale of particles are a powerful tool to investigate the link between microstructure and properties of particulate materials. At GPM2, we focus on DEM simulations dedicated to materials sciences with an in-house code (dp3D). The aim is to model powder processes (compaction, sintering) and to optimize the microstructure of powder-based materials. New developments with the open-source code LIGGGHTS are also under way.
more details on dp3D animations
DEM simulations work at the particle length scale, thus allowing a pertinent modelling of particulate materials such as powders. The objective is to use these simulations to:
Uniaxial crushing of an agglomerate with dp3D
The crushing of spherical agglomerates was simulated with quantitative comparison with experiments under SEM. Crushing strength of agglomerates and aggregates can be simulated with close link to the internal structure (porosity, defects, calcination extent, …). The close-die compaction of several agglomerates can be simulated and the resulting microstructure passed to the sintering stage of the simulation code.
a) Multilayered structured with a Nickel powder sandwiched in between two ceramic layers. b) Defects in the final Nickel layer after constrained sintering.
Sintering of complex microstructures such as composites, multilayers and powders with pore formers is tackled with DEM. For example, the constrained sintering of multilayered structures was simulated with special attention to the initiation of defects.
From a X-ray tomography image to a discrete element simulation of fracture of a porous ceramic obtained by freeze-casting.
DEM can advantageously be coupled with X-ray tomography to approach real microstructures. For example, sintered microstructures obtained from freeze-casting (collaboration with Univ. Washington) were imaged and given to our DEM code to obtain its fracture behavior.
mise à jour le 16 janvier 2019