1. Generalities#

The data structures representing the fields are:

  • sd_cham_no: field on the nodes of a mesh

  • sd_cham_geom: coordinate field for mesh nodes

  • sd_carte: field on the meshes of a mesh

  • sd_cham_elem: field on the elements of a ligrel

  • sd_resuelem: field of elementary matrices (or vectors) on the elements of a ligrel

We call « magnitude » a « vector » of components (CMP) of the field.

For example, for a displacement field: (“DX”, “DX”, “DZ”).

A discretized field is a set of quantities located on nodes, Gauss points or cells.

All the quantities of a field do not necessarily have the same components: for example, on some parts of the mesh, the nodes can have 6 CMPS of displacement (beam elements) while on other parts, the nodes only have 3 CMPS (solid elements).

The components of a quantity are a subset of the CMPS declared in the quantity catalog [D4.04.01]. To describe a quantity, in addition to its numerical values, it is necessary to know which CMPS it is; for this, we use the concept of « descriptor_quantity » which describes the presence (or not) of all the CMPS in the catalog. This concept is described below.

  • The sd_map are discretized fields on the cells of a mesh (or the late cells of a ligrel). There is 1 size per mesh,

  • sd_cham_no are discretized fields on the nodes of a mesh (or the late nodes of a ligrel). There is 1 size per knot,

  • the sd_cham_geom are coordinate fields of the nodes of a mesh. Each node carries the components (X, Y, and Z)

  • sd_cham_elem are discretized fields on the elements of a ligrel. There can be several quantities per element (for example one quantity per Gauss point or per node). Dicretization points (knots or Gauss points) may have subpoints; if so, all points have the same number of subpoints,

  • sd_resuelem are discretized fields on the elements of a ligrel. The quantities associated with such fields are the so-called « elementary » quantities: elementary matrices or elementary vectors. The set of values in a resuelem can be large, which is why the object containing these values (. RESL) has a dispersed collection structure.

Important note:

The data structures described here are not easy to use. They are SDs normally used in low-level operations: elementary calculations, assemblies, resolutions… When you want to read or write to such SDs, it is often preferable to transform them beforehand into SDs that are more convenient to use (« simple » fields). The ad hoc transformation routines: CNOCNS , CNSCNO , , , , * ** ,, ,, ,, ,, ,, ,, , ,, ,, ,, ,, ,, ,, , CGOCNS CELCES CARCES D4.06.06