Stochastic reduced-order model for dynamical structures having a high modal density in the low-frequency range

International audienceThis paper is devoted to the construction of stochastic reduced-order computational model for dynamical structures having a high modal density in the low-frequency range. The structure considered is characterized by the fact that it exhibits, in the low-frequency range, not only the classical global elastic modes but also numerous local elastic modes which cannot easily be separated from the global elastic modes. A new approach has recently been proposed for constructing a reduced-order computational dynamical model adapted to the low-frequency range. The proposed method requires to decompose the domain of the structure into subdomains. Such a decomposition is carried out using the Fast Marching Method. An adapted generalized eigenvalue problem is constructed using such a decomposition and allows an adapted vector basis to be computed. This basis is then used to construct the reduced-order computational model. The methodology is applied on a complex computational model of an automotive vehicle