3. Operands#

The first simple keywords are the ones used in the PROJ_CHAMP operator. However, some of these concepts are reused in the following phases of the macro-command (modification of the reference frames and filtering the degrees of freedom). In the macro command, the PROJ_CHAMP operator is used by default with the “COLOCATION” method (cf [U4.72.04]). But you can explicitly use the point cloud method by adding the necessary keywords detailed in the documentation of this operator.

The product concept is the same type as the input concept, defined by the keyword RESULTAT.

3.1. Keyword RESULTAT#

♦ RESULTAT

Data structure that you want to manipulate. Currently, only structures such as evol_elas, dyna_trans, dyna_harmo and mode_meca can be given as input.

3.2. Keyword MODELE_1#

♦ MODELE_1

Modele_sdaster structure associated with the result concept. This is generally the digital support model.

3.3. Keyword MODELE_2#

♦ MODELE_2

Modele_sdaster structure. This is generally the model associated with the experience. Warning: PROJ_CHAMP only works if the degrees of freedom of the nodes in model 1 are the same as those in model 2. For example, if model 1 is 3D, and therefore only has degrees of translational freedom, you cannot take a model POU_D_T (Timoshenko beam, with degrees of freedom of translation and rotation) for model 2. In this case, a BARRE model will be chosen.

3.4. Keyword PROJECTION#

◊ PROJECTION =/'OUI' [DEFAUT]

/”NON”

This keyword makes it possible to project the results of the treatment to model 2 or not.

If a step is not made, the results of the treatment override the results already present on model 1.

3.5. Operand CAS_FIGURE#

This keyword (optional) is used to guide the program towards one of the following 4 cases:

      • « 3D » The only elements of the « 1 » mesh that will be used for the projection are the volume elements: hexahedra, pentahedra, tetrahedra and pyramids. Nodes have 3 \((X,Y,Z)\) coordinates.

      • « 2D » The only elements of the « 1 » mesh that will be used for the projection are the surface elements: quadrangles and triangles. The mesh is assumed to be plane. Nodes have 2 \((X,Y)\) coordinates.

      • « 2.5D » The only elements of the « 1 » mesh that will be used for the projection are the surface elements: quadrangles and triangles. The mesh is 3D. Nodes have 3 \((X,Y,Z)\) coordinates. This is the case of « shells » immersed in 3D.

      • « 1.5D » The only elements of the « 1 » mesh that will be used for the projection are the line elements: segments. The mesh can be 2D or 3D. Nodes have 2 or 3 \((X,Y,Z)\) coordinates.

3.6. Keyword VIS_A_VIS#

We can refer to [U4.72.04] (documentation of the PROJ_CHAMP operator), for the use of this optional keyword, which makes it possible to explicitly declare the links between entities of model 1 and model 2 for the projection.

However, there is a specific feature of using VIS_A_VIS in this command: the mesh groups facing each other must have the same name in both models. If not, an error is issued.

3.7. Operand TYPE_CHAM = “NOEU”#

This keyword is used to force projected fields to be « node » fields. This keyword is used systematically (for example) by the MACR_LIGN_COUPE command because we do not know how to create fields by elements on the « fictional » beam model created by this visualization macro command.

3.8. Selecting field names#

The keyword NOM_CHAM = l_noch allows you to choose which SD RESULTAT fields you want to project. This keyword is mandatory. You can also project fields by « ELNO » and « ELEM » elements (but not « ELGA « ).

3.9. Operands MATR_RIGI, MATR_MASS#

These 2 keywords make it possible to associate (for a « fashion » data structure) their matrix with the data structure produced. They also make it possible to go back to the numbering of degrees of freedom. They are necessary if you want to use the result of the command in subsequent calculations (commands REST_GENE_PHYS, PROJ_BASE, MAC_MODES,…).

3.10. Selecting order numbers#

Confer [U4.71.00].

3.11. Operand MODI_REPERE#

◊ MODI_REPERE = _F (


Keyword factor used to define a local coordinate system for the selected entities (nodes or meshes) of Model 2.

3.11.1. Keywords TYPE_CHAM/NOM_CMP#

The MODI_REPERE operator must know the components to be transformed. A displacement field is generally used as input, which is why the entries” VECT_3D “and (” DX “,” DY “,” DZ “) are provided by default. But if we want, for example, to deal with the case of a deformation field (measured using gauges), we would write TYP_CHAM =” TENS_3D “and NOM_CMP =(” EXX “,” EYY “…)

3.11.2. Tags REPERE/VECT_X/VECT_Y/ANGL_NAUT//ORIGINE/AXE_Z#

  • REPERE = “UTILISATEUR”

The user can define the local coordinate system associated with a node himself using the data of the three nautical angles. A definition of nautical angles can be found in [U4.42.01-I1], AFFE_CARA_ELEM U4 documentation, paragraph 10.4.

  • REPERE = “CYLINDRIQUE”

To define a cylindrical coordinate system, you must give the origin (keyword ORIGINE) and the direction of the vertical axis (keyword AXE_Z).

  • REPERE = “NORMALE”

The axes of the local coordinate system are noted \((\mathrm{X1},\mathrm{Y1},\mathrm{Z1})\). In general, the sensors, for a measurement, have the axis \(\mathrm{Z1}\) according to the normal to the wall of this structure. This option allows you to calculate a coordinate system associated with this normal:

  • calculation of the vector field normal to model 1 (the most accurate); these vectors will be the \(\mathrm{Z1}\) axes of the local coordinate system,

  • projection of this field on the selected entities of Model 2,

  • explicit data of the second coordinate system; if we want the vector \(\mathrm{Y1}\) to be the same vector as \(Y\) in the global coordinate system, we write VECT_Y = (0.0,1.0,0.0)

  • We therefore need two equations to calculate the local coordinate system: one of them is given by the normal vector, the other is given by the keyword VECT_X or VECT_Y, depending on whether the additional condition relates to the vector \(\mathrm{X1}\) or \(\mathrm{Y1}\) of the local coordinate system.

  • REPERE = “DIR_JAUGE”

The user can define the local coordinate system associated with the strain gauge by entering VECT_X or/and VECT_Y. These two vectors correspond to the first two base vectors of the local coordinate system.

3.12. Operand FILTRE#

◊ FILTRE = _F (

Keyword describing, for all entities (nodes, meshes, groups of nodes,…) the degrees of freedom to maintain.

3.12.1. Keyword DDL_ACTIF#

◊ DDL_ACTIF = ddl_list

List of degrees of freedom to maintain for the result.

3.12.2. Keywords GROUP_NO/GROUP_MA#

Each degree of freedom filter corresponds to a topological entity to choose from (by default, the entire structure is selected).

3.12.3. Keyword NOM_CHAM#

♦ NOM_CHAM = night

Symbolic name of the field to be filtered. This keyword is mandatory. Among other things, it makes it possible to differentiate the DX component of the displacement field from the DX component of the speed field.

3.13. Operand EPSI_MOYENNE#

◊ EPSI_MOYENNE = _F (

Keyword factor used to calculate the average value of the deformation field on a given topological entity. This average value of the deformation field can be seen as being the information that a deformation gauge stuck to the surface in question would have delivered. This is valid if the field is not too variable on the surface on which the gauge is stuck. The user is notified if the deformation field fluctuates too much.

Each occurrence of this keyword corresponds to an average calculation on the designated entities. The calculated values are then projected onto model 2, unless the user explicitly specifies PROJECTION = “NON”. In this case, we overload the incoming concept resu_in and we put the calculation results into resu_out.

3.13.1. Keywords GROUP_NO/GROUP_MA#

This keyword indicates the topological entity on which we want to calculate the average.

3.13.2. Keyword MASQUE#

◊ MASQUE = lcmp

This keyword makes it possible to list unmeasured components of the deformation field.

3.13.3. Keyword SEUIL_VARI#

◊ SEUIL_VARI = threshold

One gives here a relative threshold value from which the user is warned if the fluctuation of one of the components of the field, which is not masked, is too far from the calculated average value. The value taken by default is equal to \(0.1\).

3.14. Operand TITRE#

◊ TITRE = title,

The title we want to give to the concept result.