Sensitivity analysis for the transverse displacements of a cracked plate using the spatial wavelet approach

In this paper, the effectiveness of the proposed technique is used for the sensitivity analysis of cracked plates, and verified theoretically and experimentally. The transverse displacements and natural frequencies of cracked plates are obtained using the fractal two-level finite element method The transverse displacements of the cracked plates are then transformed using the spatial wavelet method. The numerical and experimental results have concluded that I) the natural frequencies are not very sensitive to small cracks. The presences of the small cracks and crack locations cannot be identified effectively by examining the natural frequencies; 2) the transformed transverse displacements are more sensitive to the crack extent and change significantly at the crack locations, provided that the wavelet dilation index is high enough (i.e., the wavelet transform resolution is fine enough); 3) however, the experimental results show that if the wavelet dilation index is set too high, the crack locations cannot be detected from the transformed displacements. It is because the plate surface roughness in the experiment cases induces some local variations on the transformed displacement curve to mask the crack location. Copyright © 2005 by ASME.