The module GrainGeo creates detailed 3D models of granular structures, sintered materials, sphere packings and pilings with arbitrary object shapes.

Typical applications are replication of ceramics, soot particle filters, metamorphic rocks, polymer concrete, electrode materials, e.g., for Li-ion batteries. In general, the spectrum ranges from powders and piled granular structures to sintered materials with open or closed porosity, up to densely sintered composite materials.

The starting point for modeling a granular structure is to define initial parameters, such as grain size distribution, pore size distribution or grain shapes. By starting the creation process, randomly distributed grain structures, pilings of various digital grains and sphere packings are generated according to these parameters. Resulting target parameters are, e.g., the object volume percentage or the density of the final material. By varying the initial parameters, new materials can be created, and their properties can be optimized. Optionally, a result file (*.gdr) from GrainFind-Identify Grains can be loaded (see the GrainFind chapter) to set the initial parameters.

The structures can be further processed by a simulated sintering process, growing sediments, redistribution of the grains or by adding binder. Examples for possible structures are shown in the figure below.

With other GeoDict modules, the structures can be further analyzed and processed: Geometric properties like pore-size distribution (PoroDict) and transport properties like tortuosity, effective diffusion, and effective electrical and thermal conductivity (ConductoDict, DiffuDict) can be calculated. Flow resistivity (permeability, pressure drop), filter efficiency, filter capacity, and many more, can be computed using e.g. FlowDict, FilterDict and AddiDict. Mechanical large deformation and stress/strain curves can be simulated using ElastoDict and the charging of battery electrodes can be analyzed with BatteryDict.

The generated models are available as 3D images and can be exported for further processing using additional software. Using ExportGeo-CAD, the structures can be meshed and exported as well.