2. Purpose of the mesh interface#

The information contained in the universal file IDEAS (for versions 4, 5 and 6 and versions 1., 2., 3., 4., 5., 6., 7., 8., 9., and 10. of Master Series) is transcribed into the mesh file. This includes node coordinates, meshes, and groups of nodes and meshes. These are most often simple subfile transfers, except for meshes where node swapping is necessary.

The names created by the interface are:

  • for nodes: NO followed by the node number IDEAS,

  • for knitwear: MA followed by the item number IDEAS.

The meshes are grouped into homogeneous sub-files: TRIA., QUAD.,., TETRA., PENTA., HEXA.

for groups of nodes or meshes created by the user and named in IDEAS, the name is simply transcribed**in uppercases*:

  • 8 alphanumeric characters maximum (otherwise truncation of the name),

  • underlined white is allowed.

note

The group name cannot start with « COUL_xxx » otherwise it is ignored by the interface (an alarm message alerts the user).

  • In IDEAS, you can assign a color to each generated mesh (by default, the meshes are green). The colors are identified by a number (for example 7 for green).

To keep this information in Aster, the PRE_IDEAS interface can generate mesh groups with the name « COUL_xxx » color number IDEAS containing all the cells with the color « color number IDEAS ». To generate these mesh groups, the user must explicitly request it by CREA_GROUP_COUL = “yes” in the PRE_IDEAS command.

Without explicit user requests, these mesh groups are not created in order to limit the number of mesh groups and to avoid unnecessarily increasing the size of the mesh file.

From the associations between geometric entities and meshes, the interface builds:

  • the GROUP_MA associated with “mesh volume” in 3D or with “meshareas” in 2D. They have the name M_ VOLUi or M_ AREAi for the original geometric entity, numbered.

  • the GROUP_NO associated with “mesh volume”, “mesh area” or “curve”, which have the names M_ VOLUi, M_ AREAi, CURVEi depending on the case.

Note:

The mesh area and mesh volume no longer exist in versions 1., 2., 3., 3., 4., 5., 6., 7., 8., 8., 8., 8., 8., 9., 9., and 10. of Master Series. The user must therefore take care to define the node groups and the mesh groups that he needs for his study.

The mesh interface (PRE_IDEAS) does not transcribe the boundary conditions and loads that may be present in the universal file.