Eur. Phys. J. Plus (2019) 134: 551
https://doi.org/10.1140/epjp/i2019-12891-7

Regular Article

Effects of initial stresses on the electromechanical coupling coefficient of SH wave propagation in multilayered PZT-5H structures

¹ College of Civil Engineering and Architecture, Zhejiang University, 310058, Hangzhou, China
² Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, 310027, Hangzhou, China
³ Soft Matter Research Center, Zhejiang University, 310027, Hangzhou, China
⁴ Laboratory of Physics of Materials, Faculty of Sciences of Sfax, University of Sfax, PB 815, 3018, Sfax, Tunisia
⁵ National School of Engineers of Sfax (ENIS), Street Soukra Km 4, 3018, Sfax, Tunisia

^* e-mail: lucf@zju.edu.cn

Received: 1 January 2019
Accepted: 14 July 2019
Published online: 6 November 2019

Abstract

The electromechanical coupling factor (K²) presents a key parameter in acoustic devices that reflects the influence of piezoelectricity on the phase velocity of elastic waves. The higher this coefficient, the stronger the dependence of the characteristics of wave propagation on the electric-system parameters. Here, we investigate numerically K² for third- and fourth-order shear wave modes (SH₂ and SH₃) in arbitrarily anisotropic multilayered PZT-5H laminates with various orientations. The open-circuit (OC) and short-circuit (SC) are applied to determine this key parameter, while the SH₂ and SH₃ are chosen because they have a higher K² in comparison with other SH_m modes. Additionally, the effects of initial stresses are taken into account. We find that the initial stress has a significant influence on the SH_m (m = 2, 3 modes, especially for thick laminates. The characteristics of SH₂ and SH₃ modes are analyzed for different thickness ratios of (010)-[100] to (0 - 10 -[100] and periods of PZT-5H layered structures. Results show that K² varies with the thickness ratio and periods of the laminates. Overall, K² can reach about 30% and 44% for SH₂ and SH₃ modes in a laminate with unit thickness ratio and period. Moreover, the sensitivity of K² to the thickness of the middle layer is discussed in detail. The mechanical stresses, mechanical displacements, electric displacements and electric potentials for SH₂ mode are discussed as illustrative examples. Results demonstrate that ([(010)-[100]/(0 - 10 -[100]/(010)-[100])_N structures have some useful properties in the design of acoustic wave constructed from piezoelectric materials.