Symmetry conditions (CHECK_LINK)

This section gives information on how to link nodes with other nodes.

Important:

This kind of design variable constraints is only available with the bead controller optimization type.

Related Topics
In Other Guides
DVCON_BEAD
LINK_BEAD

Symmetry conditions can also be applied in SIMULIA Tosca Structure.bead. A LINK-condition is needed to create a symmetry condition.

The types of symmetry supported by SIMULIA Tosca Structure.bead is point, plane and rotational symmetry:

LINK_BEAD
 ID_NAME = <link_name>
 TYPE = POINT_SYM
 PLANE_SYM, AXIS_*
 ROTATIONAL_SYM, AXIS_*
 CS = <cs_name>
END_

The origin of the coordinate system referenced by the <cs_name> is the symmetry point or a point on the symmetry plane, where AXIS_* is the normal to this plane. For rotational symmetry the origin of the coordinate system is a point on the symmetry axis, where AXIS_* gives the direction.

The following figure shows an asymmetric load case without (left) and with (right) symmetry condition:

Important:
  1. AXIS_* can be AXIS_1, AXIS_2 or AXIS_3 of the chosen coordinate system.
  2. Only cartesian coordinate systems can be used for symmetry conditions.
  3. The name of the link is referenced in a DVCON_BEAD command using CHECK_LINK=<link_name>.