Rotational Symmetry (ROTATION_SYM)

Couple displacements that are rotational symmetric around an axis.

See Also
In Other Guides
LINK_SHAPE
GROUP_AUTO_DEF

CLIENT / Applicable for SHAPE_CONTROLLER SHAPE_SENSITIVITY
ROTATION_SYM OK -

To be able to couple displacements rotationally symmetric about an axis, the position and the orientation of the axis must be exactly specified. It is also necessary to specify tolerances in order to identify nodes lying rotationally symmetric relative to the axis. The mesh of the coupled node group should be rotationally symmetric. These parameters are specified as follows: 


CLIENT     = ROTATION_SYM
CLIENT_DIR = <x_1>,<x_2>,<x_3>
CS         = name_of_coord_system
TOL        = <tol_1>, <tol_2>, <tol_3>

The origin of the coordinate system referenced by CS defines a point on the axis. The direction specified by the CLIENT_DIR parameter defines the axis direction. The symmetry of the nodes assigned by ND_GROUP in the DVCON_SHAPE command is checked against the symmetry axis. Symmetric nodes are assembled into a symmetry group (a simplification of the GROUP_AUTO_DEF command, where these symmetry groups can be built according to cylindrical coordinate systems, in combination with LINK_SHAPE, CLIENT=VECTOR, and DVCON_AUTO_SHAPE). Then the main node of the symmetry group is determined and the displacements of the client nodes are calculated in such a way that they move rotational symmetric to the axis (see the following figure).



In addition, an angle can be defined to divide the search area into discrete sections:


ANGLE =  <real>