Evaluation of structural power flow using an optimized regressive discrete Fourier series
Presezniak, Flavio Augusto
Faculty of Applied Engineering Sciences
Maastricht :Shaker, 2009
Engineering sciences. Technology
Proceedings of the 4th International Conference on Optical Measurement Techniques for Structures & Systems OPTIMESS 2009 / Dirckx, J. [edit.]; Buytaert, J. [edit.]
Proceedings of the 4th International Conference on Optical Measurement Techniques for Structures & Systems OPTIMESS 2009, Antwerp, Belgium, 25-26 May 2009. - Maastricht, 2009
Evaluation of structural power flow (or structural intensity SI) in engineering structures is afield of increasing interest in connection with vibration analysis and noise control. In contrast to classical techniques such as modal analysis, SI indicates the magnitude and direction of the vibratory energy traveling in the structures, which yields information about the positions of the sources/sinks, as well as the energy transmission path. In this paper we propose a method to model operational deflection shapes, simulated or measured with a scanning laser Doppler vibrometer (SLDV). The model is a two-dimensional Fourier domain model that is estimated using a weighted non-linear least-squares method. From the wavenumber-frequency domain data thus obtained, the spatial derivatives that are necessary to determine the structural power flow are easily computed. It will be shown that the proposed method is less sensitive to measurement noise than traditional power flow estimation techniques. A numerical model of a simply supported plate excited by two shakers, phased to act as an energy source and sink, is used as a test case.