A piezoelectric transducer for weld defect detection based on first-order shear horizontal (SH1) mode

Ultrasonic guided wave is a new non-destructive evaluation (NDE) method since it offers the potential to quickly inspect defects along long length of welds. During the mode study, a shear horizontal (SH) mode has been discovered, which is particularly attractive for NDT as it is non-leaky and almost non-dispersive. However, rare weld guided transducers have been developed so far, let alone used for wide commercialization. This paper develops a new piezoelectric transducer based on the SH₁ mode at high frequency. Experiments have been carried out to validate its performance, including mode verification, energy attenuation calculation and defect detection. The results show that the transducer can work effectively and detect defects with localization errors under 3.5%, which shows great value for further theoretical study as well as engineering applications.