6. Operand OPERATION = “SOUS_STR”#

To mix ordinary finite elements and macroelements (or substructures) in the same model, it is necessary to have a mesh containing both ordinary cells and supermeshes. The operator ASSE_MAILLAGE/OPERATION = “SOUS_STR” makes it possible to constitute this « mixed » mesh by assembling an ordinary (or mixed) mesh and a mesh containing supermeshes (coming from DEFI_MAILLAGE).

This procedure uses the names of the nodes and meshes of the meshes, so it is applicable only for meshes in the format « ASTER » .

The direction of assembly is as follows:

  • All the entities of the two mesh arguments ma1 and ma2 (meshes, supermeshes, nodes, group of elements and group of nodes) are copied into the result mesh: mac.

The only shared entities are**nodes**with**same names*. It is these nodes that allow the two meshes to be assembled.

  • Treatment of entities with the same name:

  • nodes: the nodes of the second mesh with a name existing in the first mesh are not added: it is assumed that they are the same. The coordinates of the retained node are those of the node of the first mesh. An alarm is issued when the distance between the two nodes combined is greater than:

\({10}^{-6}\mathrm{.}\text{d\_refe}\)

where \(\text{d\_refe}\) is a characteristic mesh length:

\(\text{d\_refe}=\mathrm{max}(d(O,N))\)

where \(d(O,N)\) is the distance from node \(N\) to the origin of the global coordinate system.

  • meshes (or supermeshes): if the mesh ma2 contains cells with the same name as cells from the first mesh ma1, the code stops with a fatal error.

  • group of elements (or groups of nodes): if the mesh ma2 contains a group of elements with the same name as a group of cells of ma1, this one is ignored and the code emits an alarm message.