2. Data simulation

2.1. Air base

The modal base, called « in the air », is calculated with CALC_MODES. The modes are then normalized in relation to the mass. From this simulation, we get an sd_resultat mode_meca called MODEAIR.

2.2. Turbulent efforts

The force is applied to two nodes, according to an inter-spectrum with two components. Each spectrum applied has the shape of a Gaussian. The two excitations are decorrelated (inter-spectrum \((\mathrm{1,2})\) is a null function).

The operator DYNA_ALEA_MODAL calculates the modal movements from this effort for the base MODEAIR, and REST_SPEC_PHYS restores these movements on a physical basis, on 19 points only, which simulate the experimental measurement. This result is called SPECTR19.

2.3. Effort and controllability models

The user must define the experimental mesh used during the experiment, as well as the positions of the point points on which he wishes to project the identified efforts (controllability), with the associated degrees of freedom:

1. translation if you only want to identify one-off efforts,

2. translation and rotation if you want to identify specific efforts and moments.