Evaluation of dispersion characteristics of multimodal guided waves using slant stack transform

In this paper slant stack (SL) transform is presented and its application for processing of multi-modal dispersive Lamb waves snapshots is proposed. The SL transform can facilitate the evaluation of dispersion curves based on a set of signals captured at the structure׳s surface. The presented technique leads explicitly to the frequency-phase-velocity representation of the processed signals. Theory behind the technique is presented and the SL results are compared to those obtained using the 2D discrete Fourier transform. The SL is used to process data acquired from an aluminum plate and to investigate anisotropic properties of a composite plate.