Volume 35, Issue 5 (September 2012)
Dispersion Analysis in Geotechnical Laboratory Tests: Time-frequency and Time-scale Signal Transforms
Signal processing techniques are very important for the analysis of dispersion characteristics in geotechnical laboratory applications. The scope of this paper includes the study of advanced time-frequency and time-scale methods with regard to the development of an efficient method of group velocity determination based on the time-frequency behavior of propagating wave fields. The paper analyzes different time-frequency and time-scale transform methods for further use in group velocity determination as alternatives to conventional techniques. Besides the alternative itself, the presented scheme overcomes some existing problems of conventional methods in velocity determination. The advantages and disadvantages of the time-frequency and time-scale methods are presented and discussed. Finally, the applicability of given time-frequency and time-scale methods is validated by synthetic and experimental data.