460 S. Manzato et al. 45.4 Conclusions The general rules described in literature to apply frequency based dynamic substructuring to experimental data always stress that the quality of the measured FRFs must be significantly higher than those typically used in the context of experimental modal analysis. In this paper, experimental data have been collected, keeping in mind these rules, on a relatively simple aluminum structure to verify the applicability of Frequency Based Substructuring and to test different techniques to try to improve the quality of the results. The analysis focused also on using different boundary conditions to see their influence on the results. First, the results of using standard extended interface methods were presented. Then, a sensitivity study on the internal DOFs of substructure A used to overdetermine the problem was performed, showing that an optimal point selection can improve the quality of the results by reducing the number redundant information. In this perspective, future activities will further investigate this topic to try to develop rules to optimally choose the measurement point to improve the quality of the results, possibly by making use of validated numerical models in a pre-test approach. In the last section of the paper, different methods were tested to improve the quality of decoupling by enforcing reciprocity on the measured FRFs and reducing noise. In all cases, a slight improvement compared to the original results is observed, but these methods are very sensitive to the processing parameters. Also, it should be stressed that FBS generally relies on the fact that by measuring FRFs all information on the structure are present at all frequencies lines; by applying these techniques, however, some of these information might be lost and the relation between the assembled structure and the substructures partially lost. In general, it can be concluded that for this application the quality of the measured data needs to be extremely higher than in other structural dynamic applications and that a-posteriori method have only limited effects on improving the quality of the results. However, despite the decoupled FRFs are often very noisy, modal analysis can still be applied to obtain a model of the decoupled target structure. Beside the investigation of a procedure for the selection of an optimal set of measurement points, future research will aim at investigating statistical method to exploit the sensitivity of frequency based substructuring to errors in the input data and thus deriving a “more probable” set of decoupled FRFs. Acknowledgements This research was conducted in the frame of the project IWT 130936 ADVENT (Advanced Vibration Environmental Testing). The financial support of the IWT (Flemish Agency for Innovation by Science and Technology) is gratefully acknowledged. References 1. 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