Nonparametric Stochastic Modeling of Structures with Uncertain Boundary Conditions/Coupling Between Substructures

Abstract

The focus of this investigation is on the formulation and validation of a novel approach for the inclusion of uncertainty in the modeling of the boundary conditions of linear structures and of the coupling between linear substructures. This work is particularly relevant to complex structures assembled from simpler substructures as in aerospace applications. First, a mean structural dynamic model that includes boundary condition/coupling flexibility is obtained using classical substructuring concepts. The application of the nonparametric stochastic modeling approach to this mean model is next described and thus permits the consideration of both model and parameter uncertainty. Finally, the identification of the two parameters of this stochastic model, the mean boundary condition/coupling flexibility and the overall level of uncertainty, is shown and discussed. The methodology is demonstrated on three different structural dynamic models, of a rectangular plate and of two different wings.