Cyclic Symmetry Boundary Condition Generation
Description: Defines parameters for automatic cyclic symmetry boundary condition generation on an axisymmetric model.
Format:
CYSYMGEN, cid, ptol,type
Example:
CYSYMGEN, 12, 1.-6, SYMMETRIC
| Option | Definition | Type | Default |
|---|---|---|---|
| cid | Reference cylindrical coordinate system id that matches a CORD1C or CORD2C Bulk Data entry. | Integer > 0 | Required |
| ptol | Near tolerance used to identify boundary grid points for the application of cyclic symmetric boundary conditions. | Real or blank | 1.0E-5 |
| type | If mesh on cyclic boundaries is mapped, use SYMMETRIC. If mesh on cyclic boundaries is unmapped use UNSYMMETRIC. | SYMMETRIC/UNSYMMETRIC | SYMMETRIC |
Remarks:
- When set to a valid cylindrical coordinate system id, boundary conditions are automatically generated which force cyclic symmetric behavior. Grid points are automatically identified at each r-z boundary plane based on the specified near tolerance, ptol. The two symmetry planes must have identical mesh patterns.
- The near tolerance is used to identify boundary grid points for the application of cyclic symmetric boundary conditions. The actual tolerance is derived using ptol and a model reference dimension. Each r-z boundary is identified as all grid points within this tolerance at the minimum and maximum θ values of the model.
- The CYSYMGEN and CYSYMTOL model parameters provide the same functionality as this command. See Section 5, Parameters, for more information on CYSYMGEN and CYSYMTOL.