Active health system based on wavelet transform analysis of diffracted Lamb waves

摘要

In composite materials, delaminations are discontinuities producing mode conversion processes generating various outgoing modes. The Discrete Wavelet Transform allows isolating various propagation modes and extracting them in order to measure the time delay between the arrivals of the main burst and a specific out-going mode, for various propagation paths. This process permits, with a good accuracy, to localize a damage and to estimate its extension.