Crack identification in double-cracked beams using wavelet analysis

A method for crack identification in double-cracked beams based on wavelet analysis is presented. The fundamental vibration mode of a double-cracked cantilever beam is analyzed using continuous wavelet transform and both the location and depth of the cracks are estimated. The location of the cracks is determined by the sudden changes in the spatial variation of the transformed response. To estimate the relative depth of the cracks, an intensity factor is established which relates the size of the cracks to the coefficients of the wavelet transform. It is shown that the intensity factor follows definite trends and therefore can be used as an indicator for crack size. The proposed technique is validated both analytically and experimentally in case of a double-cracked cantilever beam having cracks of varying depth at different positions. In the light of the obtained results, the advantages and limitations of the method are presented and discussed.