Research on spatial crack identification of steel beam using wavelet analysis

This paper presents a method for spatial crack identification in beam based on wavelet singularity detection which is focused on transverse unsymmetrical and nonpenetrative spatial crack. A cracked beam has been simulated using three-dimensional finite element technique, and the modal parameter of its axes is extended as signal beyond the boundary by cubic spline extrapolation. Then the singal is analyzed using the continuous wavelet transform and the location of crack is identified by the maximum of wavelet coefficients at the site of the crack.The viability of the method is demonstrated by analysis of a simply supported beam which contains semi-elliptical surface crack and elliptical internal crack, respectively.The study have reference value in spatial crack identification and diagnosis in structures.