350 / 2019-10-24 09:20:04

An iterative inverse approach for reconstruction of surface cavities by guided SH waves

结构优化与结构行为分析 > 结构力学行为分析

Guided waves have great potential in engineering, such as geological inspection and ultrasonic non-destructive testing. A thorough and effective methodology concerning utilization of guided wave scattering data is required. This paper deals with an iterative approach for reconstructing cavity-like defects located on the surface of an isotropic elastic plate, using far-field reflection data of guided SH waves. By theoretical deduction, it can be proved that the cavities’ geometric shapes are approximately expressed as the spatial inverse Fourier transform of far-field reflection coefficients in the wavenumber domain, applying the Born approximation. Furthermore, the initial image can be refined by iteratively calculating the residual of reflection coefficients and adjusting the shapes of flaws until the residual reaches the minimum value. Numerical examples are given and it is shown that the reconstructed images agree well with the actual shapes of flaws.