A simple method for crack detection in plate structures based on wavelet analysis is presented. The fundamental vibration mode of a cracked plate obtained by Finite Element Method is analyzed using two-dimensional discrete wavelet transform to estimate accurately both the location and length of the cracks. The feasibility of the proposed method is demonstrated through simulation examples, which involves plates with one or more cracks of various depths at different positions and orientations, especially near the plate edges. It is demonstrated that by using this technique one can detect sub-surface cracks, which is a notable result. The proposed detection technique may serve the purpose of structural health monitoring in situations where spatially distributed measurements of structural response in regions of critical concern can be made with, for example, networks of distributed sensors, optical fibers, computer vision and area scanning techniques.

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