Observing damaged beams through their time–frequency extended signatures

We introduce in this paper a method for observing the appearance of damages in cantilever beams. The procedure is based on comparing the natural frequencies extracted from the refined time–frequency spectrum of the non-stationary Gabor transform. The comparison is realized with an algorithm for computing the Earth's mover distance (EMD) metric such that the possibility of ambient effects is canceled. The EMD is used to measure the dissimilarities on signatures of sets with different frequency values for the first 10 vibration modes.

• Observing the appearance of damages in cantilever beams.
• Natural frequencies extracted after the LASSO minimization of the adaptive time–frequency spectrum.
• Computing the Earth's mover distance (EMD) metric and canceling ambient effects.
• Efficient comparison of signatures of sets with different frequency values.