Application of continuous wavelet transform in vibration based damage detection method for beams and plates

In this paper a method for estimating the damage location in beam and plate structures is presented. A Plexiglas cantilever beam and a steel plate with four fixed boundary conditions are tested experimentally. The estimated mode shapes of the beam are analysed by the one-dimensional continuous wavelet transform. The formulation of the two-dimensional continuous wavelet transform for plate damage detection is presented. The location of the damage is indicated by a peak in the spatial variation of the transformed response. Applications of Gaussian wavelet for one-dimensional problems and reverse biorthogonal wavelet for two-dimensional structures are presented. The proposed wavelet analysis can effectively identify the defect position without knowledge of neither the structure characteristics nor its mathematical model. (c) 2006 Elsevier Ltd. All rights reserved.