Wavelet analysis of pate wave propagation in composite laminates

摘要

A new approach is presented for the analysis of transient waves propagating in composite laminates. The wavelet transform (WT) using the Gabor wavelet is applied to the time-frequency analysis of disperse plate waves. It is shown that the peaks of the magnitude of WT in the time-frequency domain are related to the arrival times of group velocity. Experiments are performed using a lead break as the simulated acoustic emission source on the surface of quasi-isotropic and unidirectional graphite/epoxy laminates. For predictions of the dispersion of the flexural mode, Minding plate theory is shown to give good agreement with the experimental results. The planar source location based on the flexural wave is performed using a triangulation method. The sue of frequency dependent arrival time of output signal and angular dependence of group velocity provides accrete results of source location for anisotropy laminates.