asgn

   'asgn' 'n'|'e'|'p'|'l'|'c'|'s'|'b'|'S'|'L'|'se'|->
          'sh'|'alpha'|'beta'|'nadapt' <value>| ->
          'netgen'|'tetgen'| ->
          'thrds' <value>|'rbe' [<value>|'mpc']| ->
          'max'|'maxr'|'maxc' [<col>]|'minc' [<col>]

This keyword is used to manipulate the behaviour of successive commands or default values.

It can be used to define the first node or element number which will be used for the next mesh generation. And it is used to redefine the leading character of new entities. The default is D for points p, L for lines l, C for combined lines (lcmb) c, A for surfaces s, B for Bodies b, Q for nurb lines (nurl) L, N for nurb surfaces (nurs) S, A for sets se and H for Shapes sh. For example

asgn p U

will assign the character U as the leading character to all newly created names of points. The automatically created names of geometric entities use 4 characters. If all possible names with the chosen leading letter are in use then the next alphabetical letter is chosen as a leading letter, so after PZZZ follows Q000. After the last letter the amount of characters per name is increased. The maximum number is 8. Each entity has its own name space. Different entities might use the same name. Remark: Currently nurbs-lines are automatically create splines sharing the same name. Nurbs-lines can not be used for other purposes than to be displayed and so far they can not be written to a file.

The method how the scale of the color fringe plot is presented can be chosen with either

asgn max

asgn maxr

or

asgn maxc m

and

asgn minc m

were 'm' is the color of the suppressed values, here magenta (see maxc).

The command is also used to control the behaviour of the surface mesh generator for unstructured triangles. This mesher [15] uses the tree parameters alpha, beta, nadapt for mesh-control. Current default is 0.4 for alpha and beta and 4 for nadapt.

The surface mesh generator is able to use multiple cores (threads). Per default the mesher uses only one thread because only in this case the mesh numbering is reproducable. But since the surface meshing of a CAD geometry can be very time consumable a default of a certain number of threads is used when the model is opened in the auto mode (cgx -a file). The actual number of threads is listed with the command “prnt info”. This defaults can be changed in the cgx.h file (NTHREADS). When using

asgn thrds 8

the next mesh generation will use 8 threads and when saving the geometry this command is stored as well. The user might use this command to store his personal number of threads in the “.cgx” file in his home directory.

Currently two different tet mesher are available [4] [5]. They can be chosen with

asgn tetgen

or

asgn netgen

In case Nastran input should be generated it is possible to switch from MPCs to RBEs when using the send command in combination with the areampc option. The value after “rbe” represents the thermal expansion coefficient of this elements:

asgn rbe 0.5e-6

It should be noted that coincident nodes are connected by MPCs either way.