3. Operands#
3.1. Keyword SOUS_STRUC#
♦ SOUS_STRUC
Keyword factor that defines all the substructures that make up the overall structure. The definition of a substructure is based on the data of its name, the macroelement associated with it and its orientation in the physical frame of reference.
3.1.1. Operand NOM#
Name of 8 characters maximum which will later be used to designate the substructure in:
3.1.2. Operand MACR_ELEM_DYNA#
Name of the concept macr_elem_dyna from the operator MACR_ELEM_DYNA [U4.65.01] which refers to the condensed model of the substructure. It should be noted that a macroelement can be used to define several substructures.
3.1.3. Operand ANGL_NAUT#
List of the 3 nautical angles, in degrees, that allow you to go from the orientation of the model that gave rise to the macro-element to that of the substructure.
Refer to operator AFFE_CARA_ELEM [U4.42.01]: Operand ORIENTATION for the definition and use of nautical angles.
3.1.4. Operand TRANS#
List of 3 translation components that make it possible to build a new substructure based on the model that gave rise to the macro-element, by applying an overall translation.
3.2. Keyword LIAISON#
♦ LIAISON
Key word: factor used to define all the interface links between substructures. A link is defined by the names of the two substructures opposite each other, and for each of them, the name of the corresponding interface.
In the case of a mesh incompatibility between the two substructures opposite each other, it is necessary to indicate which of the two whose interface will be considered to be the master (keywords GROUP_MA_MAIT *). The slave nodes that are projected onto the master interface are defined in advance by DEFI_INTERF_DYNA [U4.64.01]. The « gluing » of the 2 interfaces will be done by writing linear relationships between the degrees of freedom of the 2 faces.
Note:
It is recommended that, in the case of incompatible interfaces, the master interface be the interface whose discretization is the most crude. In the case of using classical static modes (as many as degrees of freedom), it is therefore appropriate to use the interface with the lowest number of degrees of freedom as the master interface. In the case of the use of coupling modes, this choice may be more delicate. The choice of the master interface can clearly impact the quality of the result if the two models have very different discretizations. See the discussion on this in section 5.2 .
The movements of the nodes on the slave face will be linked to the movements of their projections on the master face. For each node on the slave face, we will write 2 (in 2D) or 3 (in 3D) linear relationships.
An application of this functionality is for example the gluing of a mesh formed of linear elements (P1) onto another quadratic mesh (P2). In this case, it is rather advised to chose the quadratic face as the « slave » face.
It is possible to define a link by reduced modes (or interface modes) by the keyword OPTION.
3.2.1. Operand SOUS_STRUC_1#
Name of the first of the substructures involved on either side of the connection. It must have been defined in advance by the keyword: SOUS_STRUC.
3.2.2. Operand INTERFACE_1#
Name of the interface of the first substructure involved in the link. It must have been defined beforehand by the operator DEFI_INTERF_DYNA [U4.64.01] for the macro-element supporting the substructure.
Note:
In the case of using coupling modes (operator MODE_STATIQUE) with the MODE_INTERF keyword, it is essential that the dynamic interface be of type CRAIGB.
3.2.3. Operand GROUP_MA_MAIT_1#
◊ GROUP_MA_MAIT_1 = lgma1
This keyword allows you to designate the master substructure, regardless of the group of elements specified as input. The operator DEFI_MODELE_GENE takes care of the search for the meshes facing each other in all cases, based on the definition of the interfaces opposite (operator DEFI_INTERF_DYNA — U4.64.01). If the interface is incompatible, and the keyword is not entered, substructure 1 is defined as master.
3.2.4. Operand SOUS_STRUC_2#
Name of the second of the substructures involved on either side of the link. It must have been defined in advance by the SOUS_STRUC keyword.
3.2.5. Operand INTERFACE_2#
Name of the interface for the second substructure involved in the link. It must have been defined beforehand by the operator DEFI_INTERF_DYNA [U4.64.01] for the macro-support element of the substructure.
Note:
In the case of using coupling modes (operator MODE_STATIQUE) with the MODE_INTERF keyword, it is essential that the dynamic interface be of type CRAIGB.
3.2.6. Operand GROUP_MA_MAIT_2#
This keyword is used to designate the master substructure, regardless of the mesh group specified as input. The operator DEFI_MODELE_GENE takes care of the search for the meshes facing each other in all cases, based on the definition of the interfaces opposite (operator DEFI_INTERF_DYNA — U4.64.01). If the interface is incompatible, and the keyword is not entered, substructure 1 is defined as master.
3.2.7. Operand OPTION#
/” REDUIT “,
Allows you to choose between classical substructuring by static modes (Mac‑Neal method, Craig-Bampton harmonic or not) or by interface modes.
3.3. Keyword VERIF#
◊ VERIF
Keyword factor for verifying the consistency of the generalized model: we check that the link is compatible with the orientations and translations assigned to the substructures. The nodes of the two interfaces need*a priori* not have to be ordered in such a way that they are two at the same time. If the interface nodes are not facing each other in pairs, the code detects this state and reorders the nodes so as to put them back facing each other.
3.3.1. Operand STOP_ERREUR#
Allows you to check the consistency of the generalized model or not.
3.3.2. Operands PRECISION/CRITERE#
Indicates the precision threshold beyond which the links are incompatible. This is the distance (relative or absolute according to CRITERE) clear of which the link nodes are considered too far apart to be effectively connected.
3.4. Keyword INFO#
Keyword used to specify the level of printing.