A nearly perfect omnidirectional shear-horizontal (SH) wave transducer based on a thickness poled, thickness-shear (d15) piezoelectric ring

TL;DR

This paper introduces a novel omnidirectional shear-horizontal wave transducer based on a specially designed piezoelectric ring, capable of generating and receiving single-mode SH0 waves uniformly in all directions, enhancing NDT and SHM applications.

Contribution

The paper presents a new design of an omnidirectional SH wave transducer using a thickness poled, thickness-shear piezoelectric ring with circumferential electric field application, achieving uniform SH0 wave excitation and reception.

Findings

Excites single-mode SH0 wave effectively

Operates over a wide frequency range

Provides nearly uniform sensitivity in all directions

Abstract

The fundamental shear horizontal (SH0) wave in plates is of great importance in the field of nondestructive testing (NDT) and structural health monitoring (SHM) since it is the unique non-dispersive guided wave mode. For practical applications, a phased array system based on omnidirectional SH0 wave transducers is most useful as it can cover a wide range of a plate. However, so far very few omnidirectional SH wave transducers have been developed. In this work, we proposed an omnidirectional SH piezoelectric transducer (OSH-PT) based on a thickness poled piezoelectric ring. The ring is equally divided into twelve sectors and the electric field is circumferentially applied, resulting in a new thickness-shear (d15) mode. Finite element analysis shows that the proposed OSH-PT can excite single-mode SH0 wave and receive the SH0 wave only. Experiments were then conducted to examine the performance of the proposed OSH-PT. Results indicated that it can generate and receive single-mode SH0 wave in a wide frequency range with nearly uniform sensitivities along all directions. Considering its quite simple configuration, compact size and low cost, the proposed OSH-PT is expected to greatly promote the applications of SH waves in the field of NDT and SHM.