Quantification and imaging of corrosion wall thinning using shear horizontal guided waves generated by magnetostrictive sensors

Abstract

Ultrasonic guided wave tomography provides an imaging potential over a hidden and inaccessible damage zone. The use of shear horizontal guided waves has been proposed as an attractive technique for surface defect characterization. In this study, the quantification and imaging of corrosion wall thinning in a plate are investigated by using shear horizontal guided waves. Simulations of shear horizontal wave propagation in the specimens using hybrid boundary element method are studied in this paper. Magnetostrictive patch transducers are designed to generate and measure the shear horizontal wave mode experimentally. The quantification via imaging of wall thinning is achieved by a modified reconstruction algorithm for the probabilistic inspection of damage tomography algorithm. The comparisons of the imaging obtained by modeling data and experimental ones of defects with different shapes in the specimens are presented in this paper. The results obtained by experimental tests are comparable with that produced by boundary elements method. The present approach provides an alternative tool, that can be applied to detecting, locating and imaging the wall thinning defects in plate-like structures.