Product: Abaqus/Explicit
The adaptive mesh refinement feature:
can refine elements locally inside an Eulerian mesh;
allows the user to define various criteria for refinement;
can remove the refinement automatically once the refinement criteria are no longer met; and
is available for Eulerian elements only.
In a traditional Eulerian analysis the topology of the Eulerian mesh does not change during the analysis. Although the Eulerian mesh motion feature allows the Eulerian mesh to move in space to cover areas of interest, its ability to create a nonuniformly refined mesh that changes with time is limited. The adaptive mesh refinement feature can locally refine the mesh by subdividing elements identified by user-defined criteria. This refinement can be removed automatically during the analysis once the criteria are no longer satisfied. This feature offers great savings in computational cost over an equivalent uniformly refined mesh.
You can independently activate adaptive mesh refinement for each Eulerian section in a model. The feature applies to all of the elements in the section, and these elements are equally divided into eight subelements when refined.
| Input File Usage: | *ADAPTIVE MESH REFINEMENT, ELSET=name |
When adaptive mesh refinement occurs, more elements are added to the Eulerian mesh. You can set a limit on the maximum increase in the number of elements. The default ratio of the increment is 8.0.
| Input File Usage: | *ADAPTIVE MESH REFINEMENT, RATIO=maximum increase in number of elements/original number of elements |
You must specify at least one refinement criterion. An element will be selected for refinement if any of the criteria are met. To reduce the numerical artifacts at the mesh transition boundaries (where a fine mesh meets a coarse mesh), the elements adjacent to the selected elements are also refined. The elements are coarsened once the refinement criteria are no longer met. Table 14.1.4–1 lists all the refinement criteria available in Abaqus/Explicit.
Table 14.1.4–1 Refinement criteria.
| Refinement criteria description | Refinement criteria label | User-specified values |
|---|---|---|
| Refine elements containing material interfaces | VF | N/A |
| Refine elements that are in contact with Lagrangian bodies | CONT | N/A |
| Refine elements in which plastic deformation occurs. Not supported for the critical state (clay) plasticity model. | PEEQ | Critical value of the equivalent plastic strain |
| Refine elements near a sharp density gradient | DENSITY | Critical value of the density gradient, computed as the ratio between the change of density across element faces and the density of the material inside the element |
| Input File Usage: | *ADAPTIVE MESH REFINEMENT, refinement criteria label, value of the criteria |