Estimation of flexural wavenumbers in the presence of multiple wave components

Abstract

The separation of closely spaced spectral components is a known problem in signal processing, be it response data either in the spatial or temporal domain. Herein an experimental method based on the maximization of the correlation between measured data and an arbitrary plane wave field is investigated for its capability in distinguishing closely spaced flexural wavenumbers. Limitations arising from data sampling and windowing are considered. These processes are used along with numerical simulations as a basis to establish the boundaries within which the method successfully detects the components present. An example from experimental data is also shown, where an alternative method, the empirical mode decomposition, is applied to verify the results and to determine the accuracy of the correlation method in comparison to another existing technique.