Import ANSYS CDB File

PREFEKO supports the import of geometry from ANSYS .cdb files. By default, when exporting such files from ANSYS, the BLOCKED option is used. PREFEKO only understands this BLOCKED syntax, the UNBLOCKED version is not supported. Also regarding the element type, only the ANSYS element types 200 (filaments, triangles, tetrahedral elements, and brick elements) as well as element type 16 (pipe16, wire with a finite radius) are supported.

Figure 1. The IN - Include an external file (ANSYS CDB) dialog.

The selection of polygonal plates and quadrangles are not supported, but all other (non-selection) options discussed in the general section of the IN card is supported. It also supports an additional selection option:

Include cuboidal volume elements
Check this item to include cuboidal elements to be used with the volume equivalence principle in Feko.

The component name from the CMBLOCK is converted to the Feko label. Since the Feko label must be an integer value, only component names which are integer strings (for example, 15) or end with an underscore followed by an integer string (for example, FEED_7) will be converted to Feko labels (15 and 7 in the examples above). In all other cases (for example, for a component name PATCH) the Feko label will be set to zero.

Note: Unlike most of the other CAD import formats supported by the IN card, the ANSYS CDB file makes provision for a wire radius of the segments of type pipe16 (real constant from the associated RLBLOCK)

This is then used during the import and any setting at the IP card is ignored (the IP card radius is still used for filaments of element type 200). For dielectric bodies, one must use an ME card to specify the element type and medium indices. The ANSYS field for the material number cannot be used, since for triangles Feko requires two such material indices (medium on each side).

The user can also import points from the ANSYS CDB file similar to importing points from FEMAP or NASTRAN files. The points defined in the ANSYS CDB file will then be available in PREFEKO as points (as if they were defined by DP cards) of the form Cxxx where xxx is the index of the grid point. This may be used, for example, to attach additional structures to the geometry. In addition, the coordinate values of the points are available as variables in PREFEKO. For example, the variables #c1234x, #c1234y and #c1234z are set to the coordinates of the point with index 1234.
Note: Points are not included by default.