Tetrahedral Blocks in 3DEC

Users of UDEC will be familiar with Voronoi jointing capabilities that allow you to create polygonal blocks. This allows you to simulate a background fracturing that could represent mineral grain boundaries or some dense jointing in a rock mass. There is no such capability (yet) in 3DEC. However, you can easily create a model composed of tetrahedral blocks. Here’s how.

Create a block and zone it with tetrahedral zones.
Use the fish function below to output the zones as polyhedra in a 3DEC data file
Use new to clear the original model and then call the data file you just created to read in tetrahedral blocks.

Voila! You can then of course mesh these blocks to make them deformable. Recent updates to 3DEC have attempted to speed up calculations in which the majority of blocks are tetrahedra with a single zone.

One word of warning though: The meshing algorithm in 3DEC tends to create aligned tetrahedral at the edges, so you may want to cut away the edges to ensure a more random block pattern.

Download example.

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