Wave propagation in FG-CNT-reinforced piezoelectric composite micro plates using viscoelastic quasi-3D sinusoidal shear deformation theory

This research deals with the nonlocal wave propagation analysis of embedded nanocomposite polymeric piezoelectric micro plates reinforced by single-walled carbon nanotubes (CNTs). For the CNT-reinforced piezoelectric composite (CNTRPC) micro plate, uniform distribution (UD) and three types of functionally graded (FG) distribution patterns of single-walled CNT reinforcements are assumed. The material properties of FG-CNTRPC micro plate are assumed orthotropic viscoelastic based on Kelvin-Voigt model. The viscoelastic FG-CNTRPC micro plate subjected to 2D electro-magnetic fields is embedded in an orthotropic Visco-Pasternak foundation. Quasi-3D sinusoidal shear deformation theory is employed to establish the governing equations in which the size effects are considered using Eringen's nonlocal theory. Analytical solution is applied in order to obtain the dimensionless phase velocity, cut-off and escape frequencies. A detailed parametric study is conducted to elucidate the influences of the small scale parameter, magnetic fields, FG distributions of CNTs, damping coefficient, aspect ratio, applied voltage and elastic medium on the wave propagation behavior of viscoelastic FG-CNTRPC micro plate. Results indicate that the dimensionless cut-off and escape frequencies decrease with increasing the magnitude of small scale parameter. Furthermore, it can be concluded that CNT distribution close to top and bottom is more efficient than those distributed nearby the mid-plane for increasing the stiffness of plates. Results of this investigation can be applied for optimum design of smart composite plates as micro-electro-magneto-mechanical sensors and actuators.