Aerothermoelastic analysis of GPL-reinforced composite lattice sandwich beams based on a refined equivalent model

Abstract

For the first time, this paper investigates the temperature-dependent aerothermoelastic properties of nanocomposite pyramidal lattice sandwich beams in supersonic airflow. A nonuniform temperature distribution along the thickness is considered. The face sheets and core of the sandwich beam are fabricated from graphene platelet (GPL)-reinforced nanocomposites. A refined thermo-mechanical equivalent model is established to determine the effective shear modulus of the lattice core subjected to a nonuniform temperature distribution. Then, the core transforms into a continuum layer. Subsequently, the beams with lattice cores were modeled as equivalent sandwich structures composed of three continuum layers. The effective modulus of elasticity of the nanocomposites was calculated using the Halpin–Tsai micromechanics model combined with the mixture rule. The aerodynamic pressure was calculated using the first-order supersonic piston theory. The aerothermoelastic properties of the sandwich beam were investigated by analyzing the critical flutter aerodynamic pressure and time-dependent responses of structures. The influences of nonuniform temperature distribution, GPL reinforcements, and end restrictions on the flutter characteristics of beams are addressed using some parameter examples.