4. Other validation methods#

4.1. Validation by visual comparison of modal deformations#

This method of validation is the most direct. It can be done by printing the modal deformations in a conventional way in Salomé.

NB: in CALC_ESSAI, in the « Model Expansion » tab, it is possible to select one or two bases (in front of « Result 1 » and « Result 2 ») and to visualize them in GMSH by clicking on « Deformed ». It is currently not possible to visualize the deformations in Salomé, this development must be carried out in 2012 (by adding the possibility of superimposing the deformed ones).

4.2. Validation by comparison of FRF#

A procedure is proposed in CALC_ESSAI allowing to compare a FRF resulting from the measurement to a FRF simulated by hammer blow. This validation method is different because the comparison is made on one measurement point at a time, but over a wide frequency band. It makes it possible to verify the very validity of the modal model.

To do this, click on « FRF » in the « Model Expansion » tab. The following window appears:

_images/1000000000000216000001ABEA7256A288AAE030.png

Image 4.2-1 : simulations of FRF in CALC_ESSAI.

On the one hand, we can select a mode concept and simulate a FRF, and on the other hand, visualize a measured experimental FRF. By displaying the curves, we can obtain the following graph, produced in XMGrace:

_images/10000201000002EC000002D9C6CC9C91921B8F5C.png

Image 4.2-2 : showing FRF in XMGrace.