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Lamb Waves Decomposition and Mode Identification Using Matching Pursuit Method Buli Xu, Victor Giurgiutiu, Lingyu Yu Mechanical Engineering Department, University of South Carolina Columbia, SC 29208 xub@, giurgiut@, yu3@ ABSTRACT Matching pursuit (MP) is an adaptive signal decomposition technique and can be applied to process Lamb waves, such as denoising, wave parameter estimation, and feature extraction, for health monitoring applications. This paper explored matching pursuit decomposition using Gaussian and chirplet dictionaries to decompose/approximate Lamb waves and extract wave parameters. While Gaussian dictionary based MP is optimal for decomposing symmetric signals, chirplet dictionary based MP is able to decompose asymmetric signals, e.g., dispersed Lamb wave. The extracted parameter, chirp rate, from the chirplet MP can be used to correlate with two Lamb wave modes, S0 and A0. Keywords: Lamb wave, matching pursuit decomposition, Gabor dictionary, chirplet dictionary, structural health monitoring, Piezoelectric wafer active sensors, PWAS 1. INTRODUCTION In recent years, a large number of papers have been published on the use of Lamb waves for nondestructive evaluation and damage detection for structural health monitoring (SHM) applications. The benefits of guided waves over other ultrasonic methods is due to their: (1) variable mode structures and distributions; (2) multimode charactesr; (3) propagation for