Crack detection in plates using fractal dimension

Abstract

An effective method for detecting cracks in plate structures based on fractal dimension analysis is presented in this paper. The method is applied to the simulated fundamental vibration mode of a simply supported rectangular plate containing a crack parallel to one of its edges of arbitrary length, depth and location. The analyzed spatial response by exhibiting abrupt changes at the site of the crack allows for an accurate determination of the location and length of the crack. Additionally, the dependence of both the maximum value and the energy of the estimated fractal dimension on crack depth provide a quantitative means for the estimation of the depth of the crack. The efficacy of the proposed method is demonstrated using various examples for plates, concerning the depth, length and position of the crack. Finally, the sensitivity of the method to additive random signal noise is systematically investigated using a noise stress test. The ability of the proposed method to accurately identify the location, length and depth of cracks despite the presence of noise and its computational simplicity make it an attractive tool for practical applications in non-destructive damage identification in structures.