Investigation of SH-Wave Fundamental Modes in Piezoelectromagnetic Plate: Electrically Closed and Magnetically Closed Boundary Conditions

Aaleksey Anatolievich Zakharenko

doi:10.4236/oja.2014.42009

Abstract

It is theoretically considered the propagation (first evidence) of new dispersive shear-horizontal (SH) acoustic waves in the piezoelectromagnetic (magnetoelectroelastic) composite plates. The studied two-phase composites (BaTiO3-CoFe2O4 and PZT-5H-Terfenol-D) possess the piezoelectric phase (BaTiO3, PZT-5H) and the piezomagnetic phase (CoFe2O4, Terfenol-D). The mechanical, electrical, and magnetic boundary conditions applied to both the upper and lower free surfaces of the plate are as follows: the mechanically free, electrically closed, and magnetically closed surfaces. As a result, the fundamental modes of two new dispersive SH-waves recently discovered in book [Zakharenko, A.A. (2012) ISBN: 978-3-659-30943-4] were numerically calculated. It was found that for large values of normalized plate thickness kd (k and d are the wavenumber and plate half-thickness, respectively) the velocities of both the new dispersive SH-waves can approach the nondispersive SH-SAW velocity of the piezoelectric exchange surface Melkumyan (PEESM) wave. It was also discussed that for small values of kd, the experimental study of the new dispersive SH-waves can be preferable in comparison with the nondispersive PEESM wave. The obtained results can be constructive for creation of various technical devices based on (non)dispersive SH-waves and two-phase smart materials. The new dispersive SH-waves propagating in the plates can be also employed for nondestructive testing and evaluation. Also, it is obvious that the plates can be used in technical devices instead of the corresponding bulk samples for further miniaturization.

Highlights

The function of the piezoelectric and piezomagnetic materials in transducers is well-known that was discussed already by about half-century ago, for instance, see [1]
References [2] [3] provide the measured material constants given as percentage volume fraction (VF) of BaTiO3 in the BaTiO3-CoFe2O4 composites
It is central to state that dispersion relations (1) and (2) are valid for calculation of the velocities of the fundamental modes when the velocities Vnew10 and Vnew11 are smaller than the speed Vtem of the shear-horizontal bulk acoustic wave (SH-BAW) coupled with both the electrical and magnetic potentials

Summary

Introduction

The function of the piezoelectric and piezomagnetic materials in transducers is well-known that was discussed already by about half-century ago, for instance, see [1]. Concerning the transversely isotropic PEM plates, the material parameters of the BaTiO3-CoFe2O4 and PZT-5H-Terfenol-D laminated composite [4]-[6] are well-known, see paper [7].

Results

Conclusion