Experimental structural health monitoring of graphite-epoxy composites using signal processing: A Review

In this paper, experimental damage detection of laminated composite structures with different wavelet functions is investigated. First, a laminated composite structure is constructed using the vacuum infusion process in plate structures. Then, modal impact hammer tests and modal shaker tests are performed on the intact and delaminated structures to investigate the effects of delamination of experimental natural frequencies and mode shapes signals, respectively. Different one-dimensional wavelet functions are used to process the experimental signals and localize delamination positions. Findings show that by increasing vanishing moments, the accuracy of experimental delamination detection increases. Also, results indicate that the best wavelet function for delamination detection of the considered laminated composite structure is the Symlet wavelet function with four vanishing moments (n=۴).