This training is an introduction to continuous modeling with FLAC2D and FLAC3D. At the end of the course, participants will master the graphical interface, documentation and the main modeling steps. Concepts are illustrated using a tunnel excavation example, from building the model geometry to results analysis. This introductory course provides the foundation for more advanced use of the software, which can be covered in more specific training modules.
You can now model convex rigid polygons (2D) and polyhedra (3D). This allows modeling of non-spherical objects when the shape is of importance (granular or cohesive systems) without requiring clumps. Contact detection and resolution use a variation of the GJK (Gilbert–Johnson–Keerthi) algorithm with only one contact between two objects (i.e., no sub-contacts) to maximize efficiency. Interactions between rigid blocks and between other PFC components, such as balls, clumps, or walls, are possible using regular contact models. Similar to balls and clumps (PFC) and blocks (UDEC/3DEC), a fully dynamic solution scheme is employed.
Convex rigid block utilities include:
The following rigid block examples show contours of block velocity for a bin flow example (left) and cylindrical blocks undergoing mixing through shaking (right).
The next illustration is based on a 3DEC model that demonstrates the effectiveness of flying buttresses in a supporting a thin-walled arch. The structure is simulated as a collection of rigid blocks and the deformation under gravity loading is observed. The model is run with (left) and without (right) buttresses to examine their effect.
In addition to granular and cohesive systems, now it is easy to create bonded block models (BBM) similar to UDEC and 3DEC. For example, the following compares a PFC2D BBM (left) with a conventional PFC2D bonded particle model (BPM) undergoing a simulated unconfined, uniaxial compression test. The two model plots indicate sample damage and fragmentation. An xy chart of Axial Stress vs. Axial Strain is shown below the two model samples.