Abstract
In this paper, a new method for shape reconstruction of local plate thinning from reflection coefficients of guided SH-waves, based on guided wave scattering theory, is presented. The Green’s function for the SH-wave problem is used to express the reflected wave field in an integral form in terms of the surface shape of flaw and the total wave displacement. By introducing the Born approximation and the far-field approximation into the integral form of the reflected wave, the depth of plate thinning is obtained as a function of the horizontal coordinate by performing the inverse Fourier transform of the reflection coefficients at various frequencies. Numerical examples are given and the accuracy of proposed inverse approach is discussed by means of parametric comparisons for different wave modes, frequency ranges and various thinning shapes.
