GEOMETRY BODY GENERAL [bnam] set_outer [set_inner*][elt]
or                                              bnam APPEND/REMOVE Set_inner*

        

This command is used to create a multiple faced body with optional internal cavities.

bnam = name of the body , used for later references to the body.

set_outer = name of a set containing the surfaces that form the outer shell.

set_inner* = set names, each set containing the surfaces that form the shells that represent the cavities. One set per cavity.

elt = element type on the body, either TE4, TE10 or TE16. (See MESHING TYPES also).

In order for a general body to be defined, a set that contains a number of surfaces must exist. Ideally, the surfaces within the set will form a closed shell, with each line of the shell being contained in the definition of two and only two surfaces from the set. If this is not the case, a warning message will be generated, in which the geometric part that has caused the problem wil be highlighted. The body is created regardless of whether problems are found, although in the case of an erroneous definition, there is no guarantee that meshing will be possible.

The surfaces can be appended to the defining set in any order.

Internal cavities may also be defined using sets of surfaces. Ideally, the surfaces within each set will form a closed shell. Cavitites may be given in the initial definition of the general body, as well as added or removed once the general body has been defined. This may be undertaken with the GEOMETRY BODY GENERAL bnam APPEND/REMOVE command.

Whenever, a general body is modified the existing mesh on the body will be cancelled. In order for meshing to take place, the internal cavities must be located entirely within the outer shell. Only tetrahedral element types TE4, TE10 and TE16 may be associated with the general body. Mesh density may be controlled by the divisions on the lines that define the surfaces in the shell sets, and by the density parameter associated with those surfaces that have the Delaunay algorithm attached.

The general body may be viewed as analogous to the two-dimensional REGION, (See GEOMETRY SURFACE REGION ).

Examples:

1.

GEOMETRY BODY GENERAL B13 OUTER

Create a general (multiple sided) body B13 from the surfaces forming a closed shell that are in the set OUTER.

2.

GEOMETRY BODY GENERAL B13 APPEND CAV1 CAV2 CAV3

Add the cavities defined by the surfaces in the sets CAV1, CAV2 and CAV3 to the existing definition of B13.

3.

GEOMETRY BODY GENERAL OUTER CAV1 CAV2 CAV3 TE10

Create a general body from the surfaces that are in the set OUTER, with three internal cavities defined by the sets CAV1, CAV2 and CAV3. The body name will be generated automatically by FEMGEN. The body definition will match that resulting from application of the commands exhibited in examples 1 and 2. Element type TE10 will be attached to the body.

4.

GEOMETRY BODY GENERAL B13 REMOVE CAV3

Remove the cavity defined by the set CAV3 from the definition of the body B13.

Return Level: GEOMETRY BODY

See also the following commands

'CONSTRUCT SET'
'GEOMETRY SURFACE REGION'
'LABEL GEOMETRY BODIES'
'MESHING DIVISION'
'MESHING TYPES'
'UTILITY DELETE BODIES'
'UTILITY TABULATE GEOMETRY BODIES'
'VIEW GEOMETRY'