Determinación de parámetros modales a través del ajuste global de la respuesta

Abstract

The present study develops the application of optimization techniques via the use of Overall Adjustment of the Response to determine modal parameters for the identification method in the general case of hysteretic or structural damping. A new approach to solving the inverse problem in modal analysis is presented which enables the modal model to be determined from the system response. A decomposition method is proposed for working with complex magnitudes in product-matrix operations that allows the real and the imaginary parts to be dealt with separately. In addition, an example of this method is presented for its implementation in commercial optimization programmes. The proposed algorithm achieves a global estimation of parameters (natural frequencies, damping coficients and the modal matrix) by means of an iterative calculation process, creating a model of artificial frequency response functions related to the total degrees of freedom of the system under study. It is thus possible to obtain a set of unique, consistent solutions for these properties simultaneously processing all the information.

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