Application of Wavelet Analysis to Weld Crack Detection in Large Space Truss Structures

In this paper, the studies of wavelet analysis to weld crack detection for large space truss structures have been conducted, and a wavelet transform based method that can detect the weld crack damage in large space truss structures is proposed. Wavelet analysis, as a promising tool for damage detection, may be viewed as an extension of the traditional Fourier transform with adjustable window location and size. Merits of wavelet analysis lie in its ability to examine local data with a "zoom lens having an adjustable focus" to provide multiple levels of details and approximations of the original signal. The main idea behind the use of wavelet for damage detection purposes is based on the fact that the presence of weld cracks introduces small discontinuities in the structural response at the damaged sites, and they are detectable from the detail signals of the DWT. A numerical simulation to a large space truss structure show its suitability and effective.