Generation and reception of shear horizontal waves using the synthetic face-shear mode of a thickness-poled...

The guided wave based inspection technique has been playing an important role in modern industries due to its capability in rapid detection of large structures. Among all the wave modes in plate-like structures, the fundamental shear horizontal wave (SH₀) is of great importance since it is the unique non-dispersive mode. However, the generation and reception of SH₀ wave using piezoelectrics is always a challenge. In this work, we synthesized face-shear deformation mode in a thickness-poled piezoelectric wafer and successfully excited/received SH₀ wave in a thin aluminum plate. Firstly, the frequency response of the proposed wafer was analyzed using the finite element method (FEM) to show that the face-shear deformation can be synthesized via applying anti-parallel electric fields on different parts of the wafer. Subsequently, time-transient FEM simulations were carried out to predict its capacity in generation/reception of SH₀ wave. Finally, experiments were conducted to examine the performance of the proposed wafer on SH₀ wave generation/reception. The obtained results indicate that the synthetic face-shear piezoelectric wafer can generate SH₀ wave along two principal directions (0° and 90°) with the amplitudes symmetric along the 45° direction. The amplitude of the generated SH₀ wave reached its maxima along the principal direction and decreased to nearly zero at 45° direction, which is in good agreement with the FEM results. Besides, the wafer can only receive SH₀ wave in a wide range of frequency, i.e., it can act as an inherent wave filter. Due to its compact size and easy fabrication, the proposed wafer has a great potential in promoting the applications of SH₀ wave in nondestructive testing and structural health monitoring.