Crack identification in double-cracked plates using wavelet analysis

In this paper, vibration first mode of a plate with two all-over part-through cracks are analyzed by using discrete wavelets transform of Spline, Haar, Harmonic and Duabechies. It is observed that crack locations are detectable in values of wavelet coefficients as sudden changes. The sensitivity of the wavelet transform method with respect to the variation in type and scale of wavelet, and the variation in distance between two cracks and relative depth of cracks is also investigated. Finally, a function is proposed for determining crack characteristics by using maximum variations trend of the Spline and Harmonic wavelet coefficients with change in relative depth of cracks.