Wave Propagation in Smart Sandwich Plates with Functionally Graded Nanocomposite Porous Core and Piezoelectric Layers in Multi-Physics Environment

This research provides a mathematical model and solution for investigating wave propagation in graphene platelets (GPLs)-reinforced functionally graded (FG) metal foam plates integrated with piezoelectric actuator and sensor layers resting on an orthotropic visco-Pasternak medium in magneto-electro-thermo environment. The FG porous nanocomposite core and the actuator piezoelectric layer are exposed to steady magnetic and electric fields, respectively. The electric potential between two piezoelectric layers is governed by a proportional-derivative controller. The Halpin–Tsai micromechanics model and the Kelvin–Voigt model are adopted to express the effective elastic modulus of the FG porous nanocomposite core and material viscoelasticity of the core and piezoelectric layers, respectively. The governing equations of smart FG porous nanocomposite plates under thermal environment are derived grounded on the refined third-order shear deformation theory. Upon the validated theoretical model, the wave velocities and frequencies in plates are obtained by solving governing equations analytically. Finally, the effects of material viscoelasticity, porosity distribution and coefficient, GPL distribution and weight fraction, the plate and GPL geometries and external environment on wave propagation characteristics are demonstrated comprehensively. This work provides guidance on tunable control of wave propagation in smart sandwich plates affected by complex external environments.