Ultrasonic NDE techniques were used to investigate the properties of sediments modeled by cohesion less solid spherical particles as a function of frequency and particle size. In this presentation we show the filtering property of the media model for transmitted ultrasonic waves, their dispersion and attenuation characteristics, as a function of applied pressure on the solid components of the media model for different particle size. Special computer software for signal analysis with fast Fourier transform, both in frequency and phase space, was used to determine filtering, dispersion, and attenuation of the ultrasonic wave in the media model. Calculated results from existing theoretical models were compared to the experimental results. Our results show that the propagation velocity increases with particle size at low frequencies and decreases with particle size at high frequencies. This last behaviour is not predicted by existing theories. It was found that new modification of the existing theoretical models was necessary in order to interpret the data.
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.Vol. 4, pages 2169 - 2176 Publisher:Ashgate Publishing Company
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