Failures detection and estimation of non-stationary signals by time-scale- frequency techniques
نویسنده
چکیده
Many recent papers deal with the improvement of tools to characterize ultrasonic signal in NonDestructive Control of materials. The spectral signature of an ultrasonic signal can be characterized by a set of ultrasonic resonances related to the material shape, size and physical properties. Many methods are used for characterizing this signature either in frequency domain or in time domain. In both cases, one cannot take into account all the physical phenomena. This paper is related to the problem of characterization of materials by use of time-frequency methods. It is concerned with an application of Wigner-Ville transforms in non-destructive evaluation of materials by ultrasound, for a better segmentation of the signal (energies). This segmentation will allow to the spectral ratio method to provide better results.
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