SH Guided Wave Tomography for Structural Health Monitoring Based on Antiparallel Thickness-Shear (d15) Piezoelectric Transducers

Detecting corrosion damage is critical in the petrochemical industry as the wall thinning in tanks or pipelines may cause severe accidents, inducing loss of economics or even lives. Guided wave based tomography is a promising technique which can effectively estimate the remaining wall thickness based on the wave dispersion curves. In this work, we proposed a tomography method for structural health monitoring based the dispersive shear horizontal waves (SH
₁
), which are excited by two antiparallel thickness-shear (d
₁₅
) piezoelectric strips (APS). The probability factor and continuous condition are both introduced to the classic algebraic reconstruction technique (ART-PC) to achieve a convenient and efficient high quality reconstruction. Then the tomography experiment is conducted on a 6mm-thick aluminum plate with a 1.5mm-deep, 50mm diameter blind hole and the results show that the hole can be well reconstructed. Furthermore, the inversion image reconstructed by using ART-PC algorithm has a high accuracy and resolution, especially when compared with that reconstructed by using the classic algorithms. The proposed SH
₁
wave based tomography method in this work is expected to be widely used in petrochemical industries in near future.