Specify the frequency at which criteria for each component are checked during solution (NLADAPTIVE,,ON).
VAL1
controls the checking frequency:
If
VAL1
> 0, the program checks the nonlinear mesh adaptivity criteria everyVAL1
substeps.If
VAL1
< 0, the program checksVAL1
number of times distributed evenly throughout the load step or defined time interval.
Default: VAL1
= -1.
For mesh-quality-based and contact-based criteria, it is generally a good practice to check the criteria at every two substeps. For a contact-based cohesive zone model in a nonlinear adaptivity framework, however, checking the criteria at every two substeps can lead to a large increase in the number of elements in a small number of substeps; a larger checking interval may therefore be necessary.
For other criteria, a negative value is suggested to avoid over-refinement, as each splitting enlarges the model four or eight times for 2D and 3D, respectively. Too many splittings, therefore, can greatly enlarge a model.
To modify the time range at which criteria-checking occurs, use the
VAL2
and VAL3
arguments.
Criteria-checking does not guarantee that splitting and remeshing occurs in a given substep. A new mesh is generated only if any element meets the criteria assigned to it. When splitting and remeshing occurs, the new mesh is used in the subsequent substep.
Splitting or Remeshing Points |
---|
Because nonlinear adaptivity does not control the substep length (solution points), it cannot accurately control the number of splitting or remeshing points. For frequency checking
(NLADAPTIVE,,ON,,,- Conversely, the program may split or remesh
|
When a new mesh is created due to nonlinear adaptivity, the following message (or similar) is issued in the output file:
**** REGENERATE MESH AT SUBSTEP 7 OF LOAD STEP 1 BECAUSE OF NONLINEAR ADAPTIVE CRITERIA **** NEW MESH HAS BEEN CREATED SUCCESSFULLY. CONTINUE TO SOLVE.
Loads and boundary conditions are mapped from the old mesh to the new mesh automatically.