Plane Wave SH(0) Piezoceramic Transduction Optimized Using Geometrical Parameters

Structural health monitoring is a prominent alternative to the scheduled maintenance of safety-critical components. The nondispersive nature as well as the through-thickness mode shape of the fundamental shear horizontal guided wave mode (SH [Formula: see text]) make it a particularly attractive candidate for ultrasonic guided wave structural health monitoring. However, plane wave excitation of SH [Formula: see text] at a high level of purity remains challenging because of the existence of the fundamental Lamb modes (A [Formula: see text] and S [Formula: see text]) below the cutoff frequency thickness product of high-order modes. This paper presents a piezoelectric transducer concept optimized for plane SH [Formula: see text] wave transduction based on the transducer geometry. The transducer parameter exploration was initially performed using a simple analytical model. A 3D multiphysics finite element model was then used to refine the transducer design. Finally, an experimental validation was conducted with a 3D laser Doppler vibrometer system. The analytical model, the finite element model, and the experimental measurement showed excellent agreement. The modal selectivity of SH [Formula: see text] within a 20 [Formula: see text] beam opening angle at the design frequency of 425 kHz in a 1.59 mm aluminum plate was 23 dB, and the angle of the 6 dB wavefront was 86 [Formula: see text].