This experimental test is conducted by recording the structure’s dynamic response to an impulsive excitement taught according to a regular texture (grid), arranged specifically for this goal, with the possibility to calculate the transfer functions.
The frequency range concerned by the measures has been limited to 0-100 Hz in order to catch the of the minor vibrations modalities, which are of course more significant for the structural identification. The frequency and damping values as well as the modal forms are computed by the software after a fitting procedure of the acquired transfer functions. The floor’s fields are schematized by appropriate models to finite elements, drawn up through calculation codes. And then a numeric model to finite elements, by simulating the structural behaviour and analyzing the response to a dynamic excitement.
The continuous comparing the theoretical analysis and the experimental one enables to refine more and more the numerical model until its optimization, namely until the return of same frequencies and the same vibrating modalities which are experimentally detected. Once a satisfying match between the dynamic behaviour and the the analytical one is achieved, it is possible to individuate the equivalent characteristics magnitudes enabling to perform the static calculation.