UNCERTAINTY QUANTIFICATION IN LOW-FREQUENCY DYNAMICS OF COMPLEX BEAM-LIKE STRUCTURES HAVING A HIGH-MODAL DENSITY

The paper deals with the construction of a stochastic reduced-order model for beam-like dynamical structures having a high modal density in the low-frequency range for which the classical methods used to construct a reduced-order model are not adapted. We then use a method recently proposed which consists in constructing a basis of the global displacements and a basis of the local displacements by solving two unusual eigenvalue problems. The stochastic reduced-order model is then construct using the basis of the global displacements. The contribution of the local displacements is taken into account in the reduced-order model using a statistical approach. The theory is presented and is applied to a computational model of fuel assemblies for which the dynamical response must be characterized in terms of global displacements.

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