Quasi-linear sensitivity-based structural model updating using experimental transfer functions

Abstract

Experimental validation of a new model updating method is presented for structural mass and stiffness estimation using vibration data. The method uses transfer functions for finite element model updating via a quasi-linear sensitivity equation of the structural response. Excitation frequencies are selected in the most sensitive ranges of transfer functions for robust updating of the structural parameters. In addition, noisy regions are omitted from measured transfer functions. A least squares algorithm with appropriate normalization is used for solving the overdetermined system of equations. The method is verified using experimental data from a one-bay, one-story aluminum frame. Fast and accurate prediction of stiffness and mass parameters using a subset of measured transfer functions in selected frequency ranges illustrated the success and robustness of the method in the presence of measurement and modeling errors.