Attenuation Analysis of Lamb Waves Using the Chirplet Transform

Lamb Waves Decomposition and Mode Identification Using Matching Pursuit Method

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 dictionar...

Application of Wavelet Transform as a Signal Processing Method for Defect Detection using Lamb Waves: Experimental Verification

A Lamb wave-based crack detection method for aluminum plates health monitoring is developed in this paper. Piezoelectric disks are employed to actuate and capture the Lamb wave signals. The position of crack is assumed to be aligned with the sensor and actuator.  Extraction of high quality experimental results of lamb wave propagation in a plate-like structure is considerably complicated due to...

Model-based analysis of dispersion curves using chirplets.

Time-frequency representations, like the spectrogram or the scalogram, are widely used to characterize dispersive waves. The resulting energy distributions, however, suffer from the uncertainty principle, which complicates the allocation of energy to individual propagation modes (especially when the dispersion curves of these modes are close to each other in the time-frequency domain). This res...

Attenuation of Lamb Waves in CFRP Plates

The paper presents the Lamb wave attenuation of Carbon Fiber Reinforced Plastic (CFRP) plates on the basis of an experimental transmitter-sensor scheme. We measured separately the S0 and A0 Lamb modes of CFRP plates with three different kind of laminate lay-ups; unidirectional [0]8s (and [90]8s), cross-ply [0, 90]4s, and quasi-isotropic [0,45,-45,90]2s. Several ultrasound transmitters were used...

Adaptive "chirplet" transform: an adaptive generalization of the wavelet transform