Filter Restriction (CHECK


Applicable for	Controller (SHAPE_CONTROLLER)	Sensitivity (SHAPE_SENSITIVITY)
CHECK_TYPE = FILTER	-	OK

Use a design variable filter to smear out design node kinks. The configuration with groups allows fine granular control over different areas by choosing different filter radii or ensuring that certain areas do not interfere.

A filter restriction is activated by setting the check type (CHECK_TYPE) of the design variable constraint to FILTER. The restriction is defined by the following parameters:

ND_GROUP: The group of node for which the constraint is active. Defining a node group is mandatory.
CHECK_GROUP: The group of node that will be used in the internal check if nodes are properly supported and taken into account. ND_GROUP will be used if this parameter is not used.
RADIUS: Defines the filter radius in terms of value and whether absolute or relative units are used. If omitted, double the average edge length of the model is used.

The parameter file command might look like the following:


DVCON_SHAPE
  ID_NAME     = MY_DVCON_BEAD
  ND_GROUP    = ALL_NODES
  CHECK_TYPE  = FILTER
  CHECK_GROUP = ALL_NODES
  RADIUS      = 3.0, REL
END_

Note:

The configuration with groups allows for fine granular control and is especially important if different design areas must not interfere.
The mechanism used for this kind of filter differs from the default mechanism, which tends to lead to a better optimization convergence behavior in many cases.

Important:

The filter restriction can only be used in combination with the sensitivity-based shape optimization approach.
When a filter restriction is used during the optimization, the default filtering (usually set in OPT_PARAM) is deactivated.

Filter Restriction (CHECK_TYPE=FILTER)