3. Launch of CALC_ESSAI#

The command used to launch the macro is as follows:

CALC_ESSAI (INTERACTIF = “NON”,

EXPANSION = _F (CALCUL = MODEAIR,

NUME_MODE_CALCUL = (1,2,3,4,5,6,7,8,),

MESURE = MODCRA,

NUME_MODE_MESURE = (1,2,3,4,5,6,7,8,)),

IDENTIFICATION = _F (ALPHA = 0.0, EPS = 0.0,

INTE_SPEC = SPECTR19,

OBSERVABILITE = OBS,

COMMANDABILITE = COM,

BASE = MODEAIR),

RESU_IDENTIFICATION = (_F (TABLE = CO ( » EFFORTS « )),

_F (TABLE = CO ( » DEPL_PHY « )),

_F (TABLE = CO ( » DEPL_SYN « )),),

);

3.1. Meaning of keywords#

3.1.1. « EXPANSION » module#

The « EXPANSION » module allows you to launch the MACRO_EXPANS macro, which performs the modal expansion of experimental data on a numerical model. It uses the operators EXTR_MODE, PROJ_MESU_MODAL, REST_GENE_PHYS, and PROJ_CHAMP.

In the present test case, we extend the modes 1, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 MODCRA MODEAIR

The new aster concepts RESU_NX, RESU_EX,, RESU_ET and RESU_RD are then created in the macro command. Interactively, naming can be done interactively.

Finally, we prepare the MACS between modes the concepts created (operator MAC_MODE) and the visualization of deformations with gmsh (operator IMPR_RESU, FORMAT =” GMSH “).

3.1.2. « FLUDELA » module#

The fludela module was removed in Code_Aster version 9. It was a feature that made it possible to identify the mass, stiffness and damping coefficients added by comparing the modal bases of the identified air, water and flow structures.

NB: at the end of the command file, we show how to simulate the entry and underflow of the calculated mode base, with the operators DEFI_FLUI_STRU and CALC_FLUI_STRU (axial flow hypothesis).

3.1.3. « IDENTIFICATION » module#

The principle of the « IDENTIFICATION » tab is to identify an inter-spectrum of efforts from the data of the inter-spectrum of displacements measured on a structure.

  • cross-spectrum: keyword INTE_SPEC, we take SPEC19,

  • modal basis: keyword BASE, we take RESU_ET, obtained in the « correlation » tab,

  • observability mesh: keyword MODELE_MESURE, we take MODPROJ1,

  • controllability mesh: keyword MODELE_COMMANDE, we take MODPROJ2,

  • adjustment parameters: they are zero in the context of this test case, but are intended to be adjusted when using real measurement data (noisy).

In non-interactive mode, the output of the identification module is by default:

  • the cross-spectrum of identified efforts (called « EFFORTS »),

  • the inter-spectrum of input movements (called « DEPL_PHY »),

  • the inter-spectrum of re-synthesized movements (called « DEPL_SYNTH », compared to the previous one).

Interspectra are sd_table_function data structures. Attention: this data structure is reserved for small inter-spectra, ideally for measured data (of the order of a few dozen measurement points max). They are not suitable for large numerical data. The inter-spectral matrices are in fact square solid matrices of size \({\mathit{nb}}_{\mathit{ddl}}^{2}\).