Abstract：A split spectrum processing (SSP) algorithm was proposed to estimate the time of flight (ToF) of the damage-scattered fundamental symmetrical (S0) mode by comparing the instantaneous phase variation degree (IPVD) of the captured wave signal from benchmark with that from a damage case, so as to realize the ultrasonic guided wave-based damage identification. Wave signals captured from an intact aluminum plate (benchmark) were firstly acquired in ideal environment (without noise). Then a notch was artificially introduced into the aluminum plate and wave signals captured from the notched aluminum plate (damage case) were acquired in different environments (without and with noise). Experimental results demonstrate that even though the captured wave signal from the damage case has a low signal-to-noise ratio (SNR), the IPVD of the captured wave signal extracted using the SSP algorithm was almost not influenced by the noise. As result, the proposed SSP algorithm was capable of estimating the ToF of the damage-scattered S0 mode with high precision, regardless of the very strong noise disturbance, leading to the successful identification of the notch in the aluminum plate using triangulation algorithm.
2012, Vol. 31 
