Finite element structural updating using FRFs

In the field of the structural dynamics the accuracy of the finite-element model of a structure can be verified via experimental modal analysis. The discrepancies between the two models can be reduced using structural updating techniques. In this paper a sensitivity-based updating method is considered. This method iteratively minimizes a residual vector of correlation functions, defined on the Frequency Response Functions (FRFs), in order to find the unknown vector of the updating parameters. The solution generally relies on a least-square Bayesian technique that, in turn, requires the use of weighting matrices to reduce the effects of noisy data. The aim of the paper is the enhancement of a solution technique by providing a formulation for the definition of the weighting matrices, thus improving the overall numerical efficiency and accuracy. Both numerical analyses and experimental investigations on simple structures are carried out to validate the proposed approach.