Long-distance structural health monitoring of buried pipes based on torsional guided wave T(0,1)

In this paper, a pitch-catch piezoelectric ring array was proposed for generation and reception of the fundamental torsional wave T(0,1) in pipes according to the performance of piezoelectric transducers with different deformation mechanism. Thickness-shear d₁₅ piezoelectric ring array was employed for T(0,1) wave generation while face-shear d₂₄ piezoelectric ring array was adopted for T(0,1) wave reception. Experiments were carried out to investigate the signal-to-noise ratio of T(0,1) wave generated by the proposed transducer and the wave attenuation in buried pipes. Results indicated that the proposed transducer could detect buried pipes with different coatings over 20 m, which was very suitable for long-distance structural health monitoring of buried pipes.