3. Operands#
3.1. Operand BASE_ELAS_FLUI#
Melasflu-like concept produced by the operator CALC_FLUI_STRU [U4.66.02], which defines a set of modal bases associated with the different fluid flow velocities. The modal response of the structure for a given flow speed is decomposed on the basis corresponding to this speed. We must then specify the speed of the vital fluid for which we want to perform the calculation.
3.1.1. Keyword VITE_FLUI#
The VITE_FLUI operand must be entered if a melasflu base is used.
♦ VITE_FLUI = vitefl
Fluid flow speed for response calculation.
3.1.2. Keyword PRECISION#
◊ PRECISION = prec
Precision on the flow speed of the fluid (by default 1.E-3).
3.2. Operand MODE_MECA#
This operand makes it possible to define the basis on which the modal response is broken down. We accept concepts such as mode_meca produced by the operators CALC_MODES [U4.52.02] or DEFI_BASE_MODALE [U4.64.02].
Note:
The operands BASE_ELAS_FLUI and MODE_MECA can be used simultaneously in the case where it is desired to calculate a stress response of a wire structure subjected to the action of a flow.
This calculation case is determined by the data of a concept of the type melasflusunder the operand BASE_ELAS_FLUI, defining the modal bases of the structure at the different flow velocities, and the choice of the physical response field “ SIPO_ELNO “under the operand NOM_CHAM. The complementary data of a type mode_meca concept under the operand MODE_MECA then becomes mandatory, in order to define the field of modal constraints at the nodes of the structure.
The modal constraints are calculated in advance by the operator CALC_CHAMP [:external:ref:`U4.81.04 <U4.81.04>`], option” SIPO_ELNO “, using the standardized modal* **deformations. The operator* NORM_MODE [U4.52.11] allows the modal deformations to be normalized beforehand.
3.3. Operands NUME_ORDRE, TOUT_ORDRE, and BANDE#
These operands should only be used when the basis on which the modal response is broken down is defined by a mode_meca concept.
◊/NUME_ORDRE = l_nuor
List of the order numbers of the modes that are actually taken into account for the calculation of the physical response.
◊/TOUT_ORDRE =/'NON', [DEFAUT]
/”OUI”,
If you want to use all the modes in the database to calculate the physical response, you can choose TOUT_ORDRE =” OUI “instead of giving the list.
/BANDE = (f1, f2)
The modes that are taken into account for the calculation of the physical response are the modes of the mode_meca concept whose frequency is in the band defined by (f1 f2).
3.4. Operand INTE_SPEC_GENE#
♦ INTE_SPEC_GENE = repmoda
Interspectrum-type concept produced by the operator DYNA_SPEC_MODAL [U4.53.23] or DYNA_ALEA_MODAL [U4.53.22], which defines modal response interspectra, i.e. generalized displacement interspectra.
3.5. Operand GROUP_NO#
List of mesh node groups where physical response interspectra are calculated.
If the keyword GROUP_NO is entered, the length of the list of nodes must be equal to that of the list of components to be rendered (keyword NOM_CMP).
If several components are to be returned and the GROUP_NO keyword is entered, it is imperative to have as many node groups as there are components; each group must contain a single node.
If a component is to be rendered for several nodes, it is possible to enter one or more groups of as many nodes as required under the keyword GROUP_NO; it is therefore no longer required in this case that the groups contain a single node.
3.6. Operand GROUP_MA#
List of mesh cell groups where physical response interspectra are calculated, in case the response field is an element field (XXXX_ELNO). The mesh list should be consistent, in length and order, with respect to the list of node groups entered by the user under the GROUP_NO keyword.
Note:
In the case of a fluid-structure interaction calculation, i.e. if the keyword BASE_ELAS_FLU is entered, the keyword GROUP_MA is not taken into account and the quantities returned on a node from the fields to the elements (type ELNO) are really only the arithmatic means of the field values on the cells in the vicinity of this node.
3.7. Operand NOM_CHAM#
♦ NOM_CHAM = 'DEPL' or 'VITE' or '' or 'ACCE' or 'EFGE_ELNO' or
“SIPO_ELNO” or “SIGM_ELNO” or “FORC_NODA”
The name of the physical response field to be calculated.
Note:
The choice of the physical response field “ SIPO_ELNO “for a wire structure under flow requires the simultaneous use of the operands BASE_ELAS_FLUI and MODE_MECA * (cf [§3.1]).
3.8. Operand NOM_CMP#
♦ NOM_CMP = 'DX' or 'DY' or 'DZ' or 'SMFY' or 'SMFZ'
Names of the components of the physical response field that should actually be calculated.
Note:
The components “DX”, “DY”, and “DY”, and “DZ’are valid for the fields “ DEPL “, “ VITE “or “ “or “ ACCE” fields. The components “ SMFY “and “ SMFZ “are valid for the field “ SIPO_ELNO “ .
3.9. Operand MODE_STAT#
◊ MODE_STAT = modesty
Mode_meca concept produced by the operator MODE_STATIQUE [U4.52.14], which defines the static modes taken into account in the case of a multi-support seismic calculation where the excitation is done on the DDL.
3.10. Keyword EXCIT#
◊ EXCIT
Keyword factor to define the DDL on which the excitation is applied, in the case of a multi-support seismic calculation.
♦ GROUP_NO = l_grno
List of node groups where excitation is applied.
♦ NOM_CMP = l_ncmp
List of components to which excitation is applied.
Note:
These components must correspond to the degrees of freedom of.*support nodes. Example:* “ PRES “, “ DRZ”, “ PHI “, …
In all cases, you need as many arguments under the operand * GROUP_NOque under the operand NOM_CMP.
For fluid sources, it is the component “ PRES “that is excited.
3.11. Operand MOUVEMENT#
◊ MOUVEMENT = 'ABSOLU' or 'RELATIF' or 'DIFFERENTIEL'
Indicator characterizing the physical response to be calculated, in the case of a multi-support seismic calculation: absolute response (“ABSOLU”) by default, dynamic (“RELATIF”) or differential (“DIFFERENTIEL”) contribution of the response.
3.12. Operand OPTION#
◊ OPTION = 'DIAG_DIAG' or 'DIAG_TOUT' or '' or 'TOUT_DIAG' or 'TOUT_TOUT'
Indicator specifying the choice of calculation to be performed:
calculation of autospectra at the nodes using modal autospectra;
calculation of autospectra at the nodes using all modal interspectra;
calculation of all interspectra at the nodes using modal autospectra;
calculation of all interspectra at the nodes using all modal interspectra.
Note:
In the case where the modal response was calculated by DYNA_SPEC_MODAL [U4.53.23], the calculation choice must be consistent with the one selected beforehand in this operator. Indeed, the options “ DIAG_TOUT “or “ TOUT_TOUT “cannot be executed if you have chosen “ DIAG “in DYNA_SPEC_MODAL [U4.53.23].
The choice by default is “ DIAG_DIAG “, which corresponds to the simplest calculation case that can be made regardless of the choice selected beforehand.
3.13. Operand TITRE#
◊ TITRE = title
Text argument defining the title attached to the output interspectrum concept.