An omnidirectional shear horizontal wave transducer based on thickness-mode (d33) piezoelectric wafer active sensors

In this study, an omnidirectional shear horizontal (SH) wave acoustic transducer (OSH-WAT) is proposed, composed of a circular aluminum structure driven by twelve thickness-mode (d(33)) piezoelectric wafer active sensors (PWAS). The OSH-WAT contains six units to form an axisymmetric structure, and each unit consists of a cylinder with a cantilever beam and two cubic stubs. Two d(33) PWASs acting like a couple, as the actuation sources, are bonded on the opposite sides of the cantilever beam to drive the excitation. The thickness-mode PWASs can produce a forcing pair, which can be converted to a circumferential shear deformation by two adjacent cubic stubs, contributing to the omnidirectional SH0 wave generation. Multiphysics finite element model (FEM) is constructed based on such a design. Harmonic analysis is conducted to obtain the spectral response of a circular aluminum plate to investigate the omni-directivity of the SH0 wave excited by the OSH-WAT, so as to identify the sweet frequency bands. Thereafter, the coupled field transient dynamic FEM simulations are carried out to acquire the dynamic response of a pitch-catch active sensing procedure. A voltage signal in the form of a 5-count tone burst is applied on each d(33)-type PWAS to generate SH0 mode waves into the aluminum host plate. The received signals demonstrate the outstanding performance of the successful generation and reception of SH0 waves. The proposed OSH-WAT may possess great potential in future Structural Health Monitoring (SHM) and Nondestructive Evaluation (NDE) applications. The paper finishes with summary, concluding remarks, and suggestions for future work.

Automated summary

An omnidirectional shear horizontal wave acoustic transducer (OSH-WAT) composed of a circular aluminum structure driven by PWAS is proposed in this study. The multiphysics finite element model is used to investigate its potential in Structural Health Monitoring (SHM) and Nondestructive Evaluation (NDE) applications. The research concludes with summary, concluding remarks, and suggestions for future work.