5.1.3.3. Small Feature Suppression Controls

Most meshing failures are the result of problems with the geometry. One of the most common geometry problems is the existence of very small faces and edges that are the product of fillets, booleans, etc. These features can be sometimes be removed by using the small feature suppression options available in the mesher properties.

Small feature suppression detects all the small features in the model based on the specified tolerance, and attempts to suppress them. To mentally visualize this, consider a sphere with diameter equal to the tolerance moving along the length of a model face. If the face falls completely within the sphere, it is considered small and will be suppressed. Model edges shorter than the tolerance will also be suppressed.

Parameter Name

Discussion

Result example

Enable

Enable small feature suppression.

Tolerance Type

Small feature suppression can be based on a relative or an absolute tolerance. Only visible if Enable is True.

Relative Tolerance

Tolerance is relative to 1/10th of the diagonal of the bounding box of the structure. Recommended values are on the order of 0.001. Making this value larger will decrease the likelihood of meshing failures, but making it too large will have the undesired side effect of altering the geometry in a negative way. Only visible if Tolerance Type is Relative.

Consider 2 faces having a 1 mm wide overlapping strip as shown in the following figure (the overlap is shown in red). The diagonal of the bounding box of this structure is 2.236 cm.

If the Relative Tolerance is greater than 1/10th of the diagonal of the bounding box of the structure, the overlap area is excluded from the model and is not meshed:

Mesher_1.Get_IMeshSimMesher().SetExRelativeSmallFeatureSuppressionTolerance("0.2240"):

However, if the Relative Tolerance is less than 1/10th of the diagonal of the bounding box of the structure, the overlap area is meshed:

Mesher_1.Get_IMeshSimMesher().SetExRelativeSmallFeatureSuppressionTolerance("0.2230"):

Absolute Tolerance

Tolerance specified in length units. Recommended values are small compared to the diagonal of the bounding box of the structure. Making this value larger will decrease the likelihood of meshing failures, but making it too large will have the undesired side effect of altering the geometry in a negative way. Only visible if Tolerance Type is Absolute.

Consider 2 faces having a 1 mm wide overlapping strip as shown in the following figure (the overlap is shown in red).

If the Absolute Tolerance is greater than 1 mm, the overlap area is excluded from the model and is not meshed:

Mesher_1.Get_IMeshSimMesher().SetExAbsoluteSmallFeatureSuppressionTolerance(".00105"):

However, if the Absolute Tolerance is less than 1 mm, the overlap area is meshed:

Mesher_1.Get_IMeshSimMesher().SetExAbsoluteSmallFeatureSuppressionTolerance(".00095"):

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