Adaptive Mesh Refinement

Adaptive Mesh Refinement is available for the following simulation study types:

There are five refinement controls:

Maximum Number of Mesh Refinements

The Maximum Number of Mesh Refinements is the maximum number of mesh refinement and solution iterations the program may attempt. Once this number of refinement passes is reached, the solving phase terminates (whether the results have reached the desired accuracy or not). This option provides a means to prevent a model with diverging or unstable results from running for an excessively long time. Also, solving times can become very long if the mesh is refined to the point that an extreme number of elements are generated. In most cases, good results are achieved in a reasonable number of refinement steps (less than 8, for example).

Results Convergence Tolerance (%)

Once the %change in the results between two consecutive iterations is less than, or equal to, the Results Convergence Tolerance, the results are considered to be acceptable. No further adaptive mesh refinement or solutions iteration is performed. For any results change greater than the specified percentage, the mesh is further refined and the solution rerun. The smaller the value is, the more accurate the results must be to complete the refinement process.

Important: If the Maximum Number of Mesh Refinements is reached, the refinement process terminates whether the Results Convergence Tolerance has been reached or not.

Portion of Elements to Refine (%)

Refinement occurs at critical regions of the model (such as, where the stresses are highest in a structural analysis). This option controls how much of the model is refined. For example, at 5%, only the those elements in the top 5% with regard to the critical result are refined. At 50%, half of the elements are refined, and at 100% all elements are refined.

Note: This option is not applicable to Modal Frequencies analyses.

Frequency Mode

It specifies which vibration mode to use as the basis of the refinement process. Note: This option is only applicable to Modal Frequencies analyses.

Results for Baseline Accuracy

The choices depend on the simulation type, and this setting is not supported for Modal Frequencies studies. You can specify the desired result on which to base the convergence test regardless of whether you are using a refinement preset or custom settings. The available options are as follows: