Dynamic buckling of magnetorheological fluid integrated by visco-piezo-GPL reinforced plates

This paper deals with the dynamic buckling analysis of sandwich plates with magnetorheological (MR) fluid core and piezoelectric nanocomposite facesheets. The core is subjected to magnetic field and the facesheets are exposed to 3D electric field. Due to the piezoelectric properties of the facesheets, the top and bottom layers can be used as actuator and sensor, respectively. Hence, a proportional-derivative (PD) controller is employed to control the dynamic buckling and vibration responses of the structure. In addition, the facesheets are reinforced by with non-uniform graphene platelets (GPLs) which their equivalent material properties are obtained using Halpin-Tsai micromechanics model. The structural damping of the piezoelectric layers is considered according to Kelvin-Voigt theory. The sandwich structure is rested on orthotropic viscoelastic model with normal, shear and damping forces. Based on the sinusoidal shear deformation theory (SSDT) and piezoelasticity theory, the motion equations are derived utilizing Hamilton's principle. Applying differential cubature method (DCM), the motion equations are solved for calculating the dynamic instability region (DIR) of the structure. The influences of various parameters such as magnetic field, applied voltage, structural damping, viscoelastic medium, volume fraction and distribution of GPLs, boundary conditions and geometric parameters of the structure are shown on the dynamic buckling behavior of the system. The results are validated with other published work for indication the accuracy of the obtained results. The results reveal that by applying the magnetic field to the MR fluid core, the DIR with be happened at higher excitation frequencies.