Cross spectral density methods for measuring structure borne power flow on beams and pipes
article
Measuring acoustic intensity, structure borne wave intensity and mechanical power flow is of interest for purposes such as determining acoustic source strengths, identifying sound sources and transmission paths, studying the character of sound fields and testing conceptual approaches like Statistical Energy Analysis. With respect to the measurement methods the advent of digital equipment has stimulated the use of signal processing in the frequency domain. So-called cross spectral density methods have been reported for various applications; see, e.g., references [1-6]. The reliability of the cross spectral density method as a signal processing method is very good owing to the elegant switching techniques for the elimination of instrument phase mismatch; see reference [2]. Recently the author has been considering the feasibility of power flow measurements for pipes in the low frequency range where only bending, longitudinal and torsional waves occur. In this letter cross spectral density methods are formulated for measuring the one-dimensional power flow for these three wave types. For bending waves the method given by Pavic in references [5, 6] is used, but with modifications in respect to the use by Pavic of signal processing in the time domain and vibration transducers other than accelerometers.
TNO Identifier
228871
ISSN
0022460X
Source
Journal of Sound and Vibration, 70(1), pp. 133-139.
Pages
133-139
Files
To receive the publication files, please send an e-mail request to TNO Repository.