About Morphing areas

A morphing area (MORPH_AREA) is a node group which will be modified independently of other morphing areas during the morphing process.

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MORPH
MORPH_AREA

All nodes in one morphing area obtain the same morphing displacement in one morphing step. This may lead to unwanted sharp edges in your structure. Thus, transition zones can be introduced for each morphing area. The transition zone is formed by the nodes of the morphing area which are connected to the border of the morph area by no more edges than specified with the TRANSITION_ZONE command. These nodes will not be displaced by the same constant morphing displacement applied to the rest of the morphing area but will be moved back to an intermediate position to assure a smooth transition between, e.g., two adjacent morphing areas or a morphing area and its surrounding area.
  • For one optimization several independent (non-intersecting) morphing areas can be defined.

  • Note: All nodes in any MORPH_AREA must be part of the design area.

  • Each area will be assigned a morphing type. The supported types are :
    • NORMAL, where all nodes in the morphing area are moved (morphed) in node-normal direction
    • VECTOR, where all nodes in the morphing area are moved in the direction specified by VEC_DIR (and the coordinate system CS)
  • All definitions made for the design variables (design variable constraints and mesh smooth definitions) also apply to morphing areas. Consequently, these definitions are also considered during morphing. Thus, e.g., symmetry definitions may enforce symmetry for symmetric morphing areas even if unsymmetric morphing displacements are applied. Also, mesh smoothing ensures high mesh quality for the morphed models and thus reliable analysis results for evaluation of the model quality.

Note:

  • Mesh smoothing in general may not allow for smooth transitions between single morphing areas as all morphing areas are part of one big design area. This can only be ensured if each morphing area is surrounded by some (at least 3-5) layers of nodes which do not belong to morphing areas. If the model contains adjacent morphing areas, use the parameter TRANSITION_ZONE of the MORPH_AREA command instead for smooth results. The size of the transition zone should be in reasonable relation to the size of the morphing area and the morphing displacement (e.g. 10% of the morphing area diameter or twice as large as the morphing displacement).
  • If a morph area with TRANSITION_ZONE>0 is situated close to an edge of the geometry with an angle larger than 60° degree no transition zone is chosen for this edge.



In the above figure the transition zone with 0, 2, and 4 layers is demonstrated.