Green's function technique to model Love-type wave propagation due to an impulsive point source in a piezomagnetic layered structure

The crux of the present study is to unravel the concealed characteristics on the propagation behavior of Love-type wave through a piezomagnetic material (PMM) stratum overlying a functionally graded piezomagnetic material (FGPMM) substrate under the influence of an impulsive point source at its interfacial surface. Functional gradients in the substrate is due to the spatial variation in the elastic constants and density. The elasto-magneto-dynamical equations are laid down for the piezomagnetic medium. Green's functions are derived for the layered structure taking a point force/point charge density at the interfacial surface into account. Dispersion equation of Love-type wave is obtained with aid of admissible boundary conditions and the well known properties of Green's function. For sake of validation, the dispersion equation is reduced to fairly match with the classical Love wave equation. To demonstrate the analytical findings numerically and set forth the parametric effects, numerical data of two PMMs are undertaken for PMM stratum and FGPMM substrate. The graphical representations reveal that phase velocity of Love-type wave is significantly affected by the material constants and the functional gradients parameters allied with the piezomagnetic layered structure. The profound effects of piezomagnetic constants, magnetic permeabilities, magnifying gradient parameters and functional gradient parameter are portrayed by graphical means. A comparative analysis to trace out the piezomagnetic effect of the PMM stratum and FGPMM substrate is accomplished owing to their transverse isotropic orientational symmetry. This study may find noteworthy dynamic and practical applications towards manufacturing and optimization of piezomagnetic sensors and transducers. In addition, the obtained result may be useful for acquiring a better performance in surface acoustic wave devices and functionally graded material waveguides.