Localizing energy sources and sinks in plates using power flow maps computed from laser vibrometer measurements

This paper presents an experimental method especially adapted for the compu tation of structural power flow using spatially dense vibration data measur ed with scanning laser Doppler vibrometers. In the proposed method, the ope rational deflection shapes measured over the surface of the structure are c urve-fitted using a two-dimensional discrete Fourier series approximation t hat minimizes the effects of spatial leakage. From the wavenumber-frequency domain data thus obtained, the spatial derivatives that are necessary to d etermine the structural power how are easily computed. Divergence plots are then obtained from the computed intensity fields. An example consisting of a rectangular aluminum plate supported by rubber mounts and excited by a p oint force is used to appraise the proposed method. The proposed method is compared with more traditional finite difference methods. The proposed meth od was the only to allow the localization of the energy source and sinks fr om the experimental divergence plots.