Dual signal processing approach for lamb wave analysis

Abstract

The identification of Lamb modes is still the most difficult step in the process of damage detection. Therefore, the aim of this paper is to use a dual signal processing approach in order to better identify Lamb modes. This approach is based on the use of a relationship between the Short Time Fourier Transform (STFT) and the Two Dimensional Fourier Transform (2DFT). Indeed, one direct theoretical relationship between their amplitudes is given in the case of both monomode and multimode signals. This relationship is then numerically verified by a two dimensional finite element method. This system is suitable for defect detection and can be easily implemented for real application to structural health monitoring.