Finite Element Model Updating by Using “Output-Only” Experimental Data

In order to validate analytical models, a comparison among the results from experimental modal analysis and the analytical prediction is performed. Indeed, the practical applications of highly detailed analytical models often reveal considerable discrepancies between analytical and test results. In recent times some effort has been spent in the development of numerical procedures for updating analytical, i. e., Finite Element, spatial model using dynamic test data. Moreover, the "output-only" modal testing and analysis revive the experimental techniques for the estimate of the modal parameters due to the ease of the testing, and due to opportunity to measure the response of the structure under the actual loading and operating conditions. In this paper, the updating of a simple structure has been performed using frequency response functions achieved by "output-only" modal analysis and the results have been compared with those obtained using the frequency response functions experimentally measured via "input/output" experimental modal analysis.