Transition Zone

This section gives information on how to define a transition zone at the model's boundaries. The transition zone prevents abrupt transitions between non-design and design area. This feature is available only for sensitivity-based bead optimizations.

This page discusses:

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DVCON_BEAD

Transition Zone Definition

A transition zone restriction is activated by setting the check type (CHECK_TYPE) of the design variable constraint to TRANSITION_ZONE. 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.
  • REFERENCE_NDGR: Nodes on the border between design and non-design area. Must be a subset of ND_GROUP. Defining the reference node group is mandatory.
  • CHECK_GROUP: The group of nodes that is used in the internal check whether nodes are supported and taken into account. ND_GROUP is used if this parameter is not defined by the user.
  • FUNCTION: Defines type of interpolation function used to describe the transition: LINEAR for a 1st-order polynomial interpolation and SMOOTH for a sine curve (default).

The parameter file command might look like the following:


DVCON_BEAD
  ID_NAME        = MY_DVCON_BEAD
  ND_GROUP       = ALL_NODES
  CHECK_TYPE     = TRANSITION_ZONE
  REFERENCE_NDGR = <Node group on the boundary>
  CHECK_GROUP    = ALL_NODES
  FUNCTION       = SMOOTH
END_

Important:
  • Multiple transition zone definitions are not supported to have overlapping transition zone regions. Meaning that there can only be one transition zone feature acting on a given node.

Explanations

The following image shows how the different node groups are to be defined:



  • ND_GROUP is a subset of DESIGN_AREA.
  • REFERENCE_NDGR is a subset of ND_GROUP and NON_DESIGN_AREA

The different parameters for FUNCTION are visualized in the next image where the grey profile represents the nondesign area, blue the design area and red is ND_GROUP: