6. Operands#

6.1. Operand RESULTAT#

♦ RESULTAT = resu

Name of a result concept of type [evol_elas, evol_noli, mult_elas, mode_meca].

6.2. Operand FORCE#

◊ FORCE =/”REAC_NODA” [DEFAUT]

/”FORC_NODA”

Name of the field to be post-processed to extract the nodal reactions. See documentation [U4.81.04].

6.4. Operands AMOR_REDUIT/MODE_CORR/SPEC_OSCI/ECHELLE//MODE_SIGNE/COMB_DIRECTION#

These operands are only used in the case of a modal-spectral calculation, i.e. when MODAL_SPECTRAL = “OUI”.

6.5. Operand AMOR_REDUIT#

♦ AMOR_REDUIT = love [L_r]

This operand makes it possible to provide the list of reduced amortizations in the form of a list of reals (L_r). If the user only provides one value, it is retained for all modes.

6.6. Operand MODE_CORR#

The modal base is generally incomplete. The evaluation of the major of the response to seismic excitation therefore requires correction by a term representing the static contribution of the neglected natural modes in each direction of the earthquake.

For each direction of the earthquake, this correction is carried out by adding to the modal base, a pseudo‑mode \(\Psi\) obtained from a static mode \(\varphi\), the field of movement of the nodes of the structure subjected to uniform acceleration in the direction considered defined by:

\(K\varphi =M\delta\)

\(K\) structural stiffness matrix
\(M\) mass matrix of the structure
\(\delta\) unit field in the direction of the earthquake

The pseudo-mode \(\Psi\) is obtained by subtracting the static contributions of the modes taken into account:

\(\Psi =\varphi -\sum _{r=1}^{\mathrm{nmod}}\frac{{p}_{r}}{{\omega }_{r}^{2}}{\Phi }_{r}\) with:

\({\Phi }_{r}\) clean index \(r\) mode
\({p}_{r}\) management participation factor \(\delta\)

In this direction \(\delta\), for each quantity, the contribution of the neglected modes is given by:

\({R}_{t}={R}_{s}-\sum _{r=1}^{\mathrm{nmod}}{R}_{r}\)

\({R}_{s}\) is the quantity associated with static mode

◊ MODE_CORR = mode_corr [mode_meca]

This keyword makes it possible to provide the \(\varphi\) displacement field (s) of the nodes of the structure subjected to uniform acceleration in one (or more) direction (s), field (s) calculated by the operator MODE_STATIQUE with the keyword PSEUDO_MODE [U4.52.14].

The acceleration of the selected pseudo-mode corresponds to the acceleration read from the spectrum at the frequency of the last mode of the modal base at the lowest modal damping.

6.7. Operands SPEC_OSCI and ECHELLE#

6.8. Operand MODE_SIGNE#

◊ MODE_SIGNE =/”NON” [DEFAUT]

/”OUI”

This operand allows you to define whether torsors CQC should be signed. If this is the case, we recover the sign of the torsors obtained under unit acceleration (from the concept given in MODE_CORR) and we apply these signs to the components of the torsor CQC.

6.9. Operand COMB_DIRECTION#

◊ COMB_DIRECTION =/”QUAD” [DEFAUT]

/”NEWMARK”

This operand makes it possible to define how to combine the contributions of the 3 directions. Two choices are possible, defined in paragraph 5.1.4,

6.10. Keyword-factor COUPURE#

Repeatable keyword used to define one or more breaks.

6.10.1. Operand NOM#

♦ NOM = name, [Kn]

This operand allows you to define a name for the break to allow it to be located in the output table.

6.10.2. Operands GROUP_MA and TOUT#

♦/TOUT = “OUI” [Kn]

/GROUP_MA = gma [group_ma]

This operand makes it possible to define the part of the model whose reaction on the group of nodes is sought to be evaluated.

6.10.3. Operand GROUP_NO#

♦ GROUP_NO = no, [group_no]

This operand allows you to define the group of nodes where you want to extract the reaction.

6.10.4. Operand POINT#

♦ POINT = (x1, y1, z1), [L_r]

This operand makes it possible to define the geometric position of the point where the torsor will be calculated. This operand has a particular influence on the values of the calculated moments (the reactions being invariant).

6.10.5. Operands AXE_X, AXE_Y, AXE_Z, and VERI_ORTHO#

◊ AXE_X =/(1, 0, 0), [DEFAUT]

/(x1, y1, z1), [L_r]

◊ AXE_Y =/(0, 1, 0), [DEFAUT]

/(x1, y1, z1), [L_r]

◊ AXE_Z =/(0, 0, 1), [DEFAUT]

/(x1, y1, z1), [L_r]

These operands make it possible to define the local coordinate system in which the torsor will be expressed.

The VERI_ORTHOpermet operand to activate or not the verification of the orthogonality of the specified axis system.