Wave propagation of embedded viscoelastic FG-CNT-reinforced sandwich plates integrated with sensor and actuator based on refined zigzag theory

The present research deals with general wave propagation in a piezoelectric sandwich plate. The core is consisted of several viscoelastic nanocomposite layers subjected to magnetic field and is integrated with viscoelastic piezoelectric layers subjected to electric field. The piezoelectric layers play the role of actuator and sensor at the top and bottom of the core, respectively. The core layers are composed of temperature-dependent polymeric layers which reinforced by functionally graded carbon nanotubes (FG-CNTs). The material properties of the nanocomposite layers are estimated based on the extended mixture rule and also the Kelvin-Voigt model is employed to consider the viscoelastic properties of the structure. It is assumed that the structure is embedded in a viscoelastic foundation which is simulated according to orthotropic visco-Pastemak model. The governing equations of the structure are developed on the basis of refined piezoelasticity zig-zag theory and Hamilton's principle. An analytical solution is applied to obtain the phase velocity, cut-off and escape frequencies. Furthermore, a proportional-derivative (PD) controller is employed to control the phase velocity in the structure. The effect of various parameters such as geometric constants, viscoelastic foundation, structural damping coefficient, applied voltage, volume fraction and distribution types of CNTs, temperature changes and magnetic field on the analysis and control of the wave propagation in the smart nanocomposite structure is examined. The results show that the applied voltage to the actuator and the exerted magnetic field to the core can be considered as effective parameters to control the wave propagation in the system. (C) 2017 Elsevier Ltd. All rights reserved.