3. Operands#
3.1. Operand MATR_RIGI#
♦ MATR_RIGI = rigi
Rigidity matrix of the isostatic or hyperstatic structure.
3.2. Operand MATR_MASS#
◊ MATR_MASS = mass
Mass matrix of the isostatic or hyperstatic structure.
3.3. Operand CHAM_MATER#
◊ CHAM_MATER = chmat
The name of the material field.
3.4. Operand CARA_ELEM#
◊ CARA_ELEM = character
Name of the characteristics of the elements of beams, shells, etc.
3.5. Nature of the solicitations applied#
3.5.1. Keyword MODE_STAT#
♦/MODE_STAT
Keyword factor for the definition of static modes with unitary imposed displacement. These modes are used to determine the load due to the multi-support training movement under seismic excitation (operator CALC_CHAR_SEISME [U4.63.01]) (cf. reference [R4.05.01]) or to introduce movements to multi-support anchors in spectral analysis (operator COMB_SISM_MODAL [U4.84.01]) (cf. reference [R4.05.03]). See example §4.1.
3.5.1.1. Operands TOUT/GROUP_NO#
Calculate the modes on all system nodes that have blocked ddls.
/GROUP_NO = g_noeu
Calculation of modes on g_noeu node groups (subset of blocked nodes).
3.5.1.2. Operands TOUT_CMP/AVEC_CMP/SANS_CMP#
Calculation of the modes on all the components locked at the nodes defined previously.
/AVEC_CMP = l_cmp
Calculation of the modes on the components mentioned only.
/SANS_CMP = l_cmp
Calculation of the modes by excluding the components mentioned.
3.5.2. Keyword FORCE_NODALE#
/FORCE_NODALE
Keyword factor for the definition of static modes with unitary imposed force. These modes are used to complete a modal base of natural vibration modes (operator DEFI_BASE_MODALE [U4.64.02] or DYNA_ALEA_MODAL [U4.53.22]). See reference [R5.06.01] and see example §4.2.
3.5.2.1. Operand TOUT/GROUP_NO#
Calculation of modes on all system nodes that have free ddls.
/GROUP_NO = g_noeu
Calculation of modes on g_noeu node groups.
3.5.2.2. Operands TOUT_CMP/AVEC_CMP/SANS_CMP#
Calculation of modes on all free components at the nodes defined previously.
/AVEC_CMP = l_cmp
Calculation of the modes on the components mentioned only.
/SANS_CMP = l_cmp
Calculation of the modes by excluding the components mentioned.
3.5.3. Keyword PSEUDO_MODE#
/PSEUDO_MODE
Key word factor for the definition of static modes (or pseudo-modes) with unitary imposed acceleration. These modes are used to complete a modal base of natural vibration modes (operator DEFI_BASE_MODALE [U4.64.02] or DYNA_ALEA_MODAL [U4.53.22]) (cf. reference [R5.06.01]), to determine the correction modes in spectral analysis (operator COMB_SISM_MODAL [U4.84.01], keyword MODE_CORR) (cf. reference [R4.05.03] ). We treat the single-support case (operands AXE/DIRECTION, see example §4.3) or multi-press (operand GROUP_NO and * CMP, see example §4.4).
3.5.3.1. Operands AXE/DIRECTION/NOM_DIR#
Calculate modes along the given global coordinate system axes (l_axis), these axes being \(\text{'}X\text{'}\), \(\text{'}Y\text{'}\), and \(\text{'}Z\text{'}\).
/♦ DIRECTION = l_dir
Calculate the mode in the given direction (l_dir)
(l_dir): director vector with 3 components.
User name that you want to give to the mode calculated in the direction (\({n}_{\mathrm{dir}}\)). By default the name is DIR_N, \(N\) being the static mode number. This name is mandatory.
3.5.3.2. Operands TOUT/GROUP_NO#
Calculation of modes on all system nodes.
/GROUP_NO = g_noeu
Calculation of the modes on the groups of nodes g_node.
3.5.3.3. Operands TOUT_CMP/AVEC_CMP/SANS_CMP#
Calculation of the modes on all the components at the nodes defined above.
/AVEC_CMP = l_cmp
Calculation of the modes on the components mentioned only.
/SANS_CMP = l_cmp
Calculation of the modes by excluding the components mentioned.
3.5.4. Keyword MODE_INTERF#
/MODE_INTERF
Key word factor for the definition of coupling modes. These modes are used to complete a modal base of natural vibration modes (operator DEFI_BASE_MODALE [U4.64.02] or DYNA_ALEA_MODAL [U4.53.22]). See reference [R5.06.01] and see example §4.2.
3.5.4.1. Operand TOUT/GROUP_NO#
Calculate modes on all system nodes that have blocked degrees of freedom.
/GROUP_NO = g_noeu
Calculation of modes on g_noeu node groups.
3.5.4.2. Operands TOUT_CMP/AVEC_CMP/SANS_CMP#
Calculation of the modes on all the components locked at the nodes defined previously.
/AVEC_CMP = l_cmp
Calculation of the modes on the components mentioned only.
/SANS_CMP = l_cmp
Calculation of the modes by excluding the components mentioned.
3.5.4.3. Operand NB_MODE#
♦ NB_MODE = nbmod
Number of modes to be calculated. For the moment, it is not possible to specify a frequency band of interest, or the maximum frequency of the modes to be calculated. The user must therefore estimate by himself the number of modes to take into account. The list of frequencies associated with the interface modes makes it possible to determine the number of modes to be taken into account in the calculation for the reduced model.
3.5.4.4. Operand SHIFT#
Shift frequency used to calculate interface modes. The choice of this value makes it possible to improve the precision of the calculation of the modes. It is possible to choose a shift value corresponding to 10% of the first expected natural frequency for the coupling modes. The arbitrary value by default is set to \(1\mathit{Hz}\).
3.6. Keyword SOLVEUR#
◊ SOLVEUR =…
This factor keyword is optional: it allows you to choose the linear solver used in certain parts of the algorithm. Since the syntax is common to several commands, please refer to the [U4.50.01] manual.
Note: for the keyword MODE_INTERF, we must solve linear systems but for these, the solver is chosen « hard » in the programming (LDLT if there are very few ddls and MUMPS if there are more).
3.7. Operand TITRE#
◊ TITRE = title
Attached to the concept produced by this operator [U4.03.01].
3.8. Operand INFO#
◊ INFO
Indicates the level of printing information on the file « MESSAGE »:
1: no printing
2: printing of the calculated static modes.