De Rosa S., Franco F.

Previous theoretical results compared with wind tunnel measurements have been devoted to the analysis of the plate response under a turbulent boundary layer excitation. Specifically these past activities have demonstrated the possible role played by the correlation area when analysing the effect of transducer mass(es). The present work represents a further step toward the same research goal. It has been performed by using a theoretical model build to get the stochastic response of a reference plate with a single concentrated mass and the configurations with two added masses. The solution responses have been built by using modal expansions with exact integrations, since a simply supported test plate was considered under the turbulent boundary layer excitation model proposed by Corcos (separable variables). The models of the plate and the turbulent boundary layer are the simplest possible, but the formulation of the problem contains all relevant parameters and it could be quickly exported in numerical predictive codes. The mass singularities were introduced by using Dirac functions directly in the generalised mass matrix, that is the mass operator projected on the modal base. The enclosed results seem to demonstrate the role played by the correlation area associated with such random and convective load. In fact, for the asymptotical flow speed available in the wind tunnel facility at the DPA, two main effects were measured and predicted: (i) the usability of the standard literature formula for analysing the effect of the transducer mass, and (ii) the transducer mass is not able to sense the presence of another mass outside of its correlation area. Particular attention was devoted to the application of the exact and validated theoretical model for increasing flow speeds. A comparison between configurations loaded with stochastic convective and non-convective excitations is discussed, too.