ansys.mapdl.core.Mapdl.dsym#

Mapdl.dsym(lab='', normal='', kcn='', **kwargs)#

Specifies symmetry or antisymmetry degree-of-freedom constraints on nodes.

Mechanical APDL Command: DSYM

Parameters:
labstr

Symmetry label:

  • SYMM - Generate symmetry constraints as described below (default).

  • ASYM - Generate antisymmetry constraints as described below.

normalstr

Surface orientation label to determine the constraint set (surface is assumed to be perpendicular to this coordinate direction in coordinate system KCN ):

  • X - Surface is normal to coordinate X direction (default). Interpreted as R direction for non- Cartesian coordinate systems.

  • Y - Surface is normal to coordinate Y direction. θ direction for non-Cartesian coordinate systems.

  • Z - Surface is normal to coordinate Z direction. Φ direction for spherical or toroidal coordinate systems.

kcnstr

Reference number of global or local coordinate system used to define surface orientation.

Notes

Specifies symmetry or antisymmetry degree-of-freedom constraints on the selected nodes. The nodes are first automatically rotated (any previously defined rotations on these nodes are redefined) into coordinate system KCN, then zero-valued constraints are generated, as described below, on the selected degree-of-freedom set (limited to displacement, velocity, and magnetic degrees of freedom) ( dofsel ). Constraints are defined in the (rotated) nodal coordinate system, as usual. See the d and nrotat commands for additional details about constraints and nodal rotations.

This command is also valid in PREP7.

Symmetry or antisymmetry constraint generations are based upon the valid degrees of freedom in the model, that is, the de grees of freedom associated with the elements attached to the nodes. The labels for degrees of freedom used in the generation depend on the Normal label.

For displacement degrees of freedom, the constraints generated are:

This command contains some tables and extra information which can be inspected in the original documentation pointed above.

For velocity degrees of freedom, the constraints generated are:

This command contains some tables and extra information which can be inspected in the original documentation pointed above.

For the 2D vector magnetic degree of freedom, AZ, symmetry is naturally satisfied and the SYMM label generates no constraints. The ASYM label generates flux parallel conditions (flux flows parallel to the surface).

This command contains some tables and extra information which can be inspected in the original documentation pointed above.