Temperature- and moisture-dependent aeroelastic stability of graphene platelet reinforced nanocomposite lattice sandwich plates subjected to supersonic flow

Abstract

In this work, we investigate the aero-thermo-elastic properties of graphene platelet (GPL)-reinforced nanocomposite lattice sandwich plates with pyramidal truss cores under supersonic airflow by considering the temperature- and moisture-dependent properties for the first time. GPLs in the face sheets are uniformly distributed or in graded form, and the trusses of the lattice cells are uniformly reinforced by GPLs. The effective modulus of elasticity of the GPL-reinforced nanocomposite is obtained using the Halpin–Tsai model, while the rule of mixture is used to estimate the Poisson's ratio and mass density of nanocomposite. Through the stress and deformation analysis of a pyramidal cell, the equivalent transverse shear modulus of a lattice-sandwich-core layer is determined; then, the composite lattice sandwich plate is transformed into a three-layered-sandwich structure. The kinematic relationships of the face sheets and lattice core layer are established using Kirchhoff plate theory and first-order shear deformation theory, respectively. The aerodynamic load resulting from the supersonic flow is obtained using piston theory. The equations of motion governing the flutter behaviors of simply supported sandwich plates under supersonic flow are derived with the help of a standard Lagrange process and assumed mode method. A comprehensive parameter study is conducted to explore the effects of temperature, moisture, GPL distribution pattern, and GPL weight fraction on the aero-thermo-elastic flutter characteristics of the nanocomposite lattice sandwich plates.