Piezoelectric composite frequency steerable acoustic transducers for impact monitoring

Abstract

This paper presents a novel piezoelectric composite frequency steerable acoustic transducers (PC-FSATs) for impact monitoring. Unlike conventional impact monitoring systems, which generally demand dense sensor networks and complex detection algorithms, PC-FSATs utilize merely two channels for achieving large-area monitoring, rendering significant system simplification and cost reduction. The PC-FSATs leverage the frequency-dependent spatial filtering mechanism, establishing a direct correlation between the elastic wave propagation direction and the frequency content of the received signal. By identifying the frequency components of the incident wave, the impact orientation can be accurately evaluated. The proposed PC-FSAT is comprised of flexible printed circuits with embedded, radially oriented piezoceramic fibers sandwiched within the central layers, which augments the transducer’s directional sensitivity while imparting favorable sensor flexibility. This research initiates with the analytical formulation of the frequency-wavenumber beam steering mechanism for the transducer design. Subsequently, finite element simulations are carried out to demonstrate the impact detection principle. Furthermore, impact monitoring and localization experiments are performed on a drop-ball platform. The results demonstrate that the proposed system can accurately locate the impact event with only a pair of transducers. This novel transducer offers a promising solution for the development of cost-effective, reliable, and versatile impact monitoring systems, with potential applications in industries such as aerospace, automotive, and civil engineering. The paper finishes with summary, concluding remarks, and suggestions for future work.