Dispersion compensation and mode separation of the ultrasonic guided waves

The application of ultrasonic guided waves has been got considerable attentions in non-destructive evaluation (NDE). However, the mode overlap and dispersion problem of guided waves are still challenging. In the present study, we used the spectral phase and time delay function to model the guided dispersion transfer system, and developed a compensation algorithm of single mode dispersion. Aiming to overcome the unsolved difficulty of multimode processing, dispersion compensation was then combined with the mode separation. Simulations of the Lamb modes A₀, A₁ and S₀ illustrated that the proposed algorithm is capable of synthesizing and compensating of single mode dispersion. Furthermore, using the selectively compensation, the individual modes can also be extracted from the multimodal guided signals. The study is helpful for the signal processing of multimodal guided dispersion.