Numerical approximations on the predictive responses of plates under stochastic and convective loads

Abstract

The quality of the predictive structural (and structural-acoustic) response of an elastic (structural) domain, under a random and convective load, is analyzed here through a discussion of the main steps of a numerical procedure.The structural response of a plate, due to a known wall pressure distribution, is derived in modal coordinates according to a finite element scheme. The modal basis can include the dry or wet (aeroelastic) structural mode shapes: in the present analysis only the in vacuum eigenvectors are used.For this problem, the transformation of the pressure distribution into discrete locations is one of the most critical steps that depends on (i) the model assumed for wall pressure fluctuation description (the assumed turbulent boundary layer model), (ii) the integration scheme and (iii) the frequency range. These three aspects are the main goals of this work. In particular, it is presented the sensitivity of the structural response toward the adopted numerical approximations.The transformation of the pressure distribution into discrete locations can be computationally expensive for the desired level of the required numerical approximation. The use of consistent formulation, in the finite element scheme, can be sometimes unfeasible. Some numerical approaches, dealing with the high frequency bands, are analyzed and some enhancements are proposed aiming at a reduction of the computational cost.