Constant Strain Tetrahedra Over Cubic Grid Meshes?

Hi everyone,

I’m seeking clarification regarding FLAC and 3DEC. While it’s commonly known that these software applications employ the Finite Difference Method (FDM), I’ve observed that they utilize Constant Strain Tetrahedra instead of the traditional cubic grid meshes. In 3DEC, each polyhedral block is subdivided into an internal finite difference mesh consisting of constant-strain tetrahedral elements. Could someone elaborate on the rationale behind this decision and its potential implications?

Many Thanks,

Hi @VijayKiranKota !

The choice for tetrahedral meshes in most softwares is due to their versatility: with tetrahedra, you can discretize (theoretically) any shape, which is not the case with cubes. Most notably in 3DEC, you will meet joint intersections with possibly sharp angles that cannot be discretized using 6 sided elements.

I might have misunderstood your question, let me know!