▎ 摘　　要

The size dependent thermal buckling analysis of composite micro plate is studied in this paper based on modified couple stress theory (MCST) and sinusoidal shear deformation theory. The composite micro plate is composed of epoxy reinforced with functionally graded graphene nanoplatelets which is distributed along the thickness direction based on various distributions (parabolic, linear and uniform distributions). After calculation of effective material properties including modulus of elasticity and Poisson ratio of composite plate, Halpin-Tsai model and rule of mixture, the governing equations are derived based on principle of virtual work. The in-plane mechanical and thermal loads are included in the work of external loads. The novelty of this work is the application of a modified couple stress theory to predict the mechanical and thermal buckling loads of micro plate reinforced composites. The effect of weight fraction of graphene nanoplatelets and various distributions of reinforcement was studied on the mechanical and thermal buckling loads. It is concluded that with increase of weight fraction of graphene nanoplatelets, the mechanical buckling loads are increased for all distributions, while the thermal buckling loads are increased for parabolic distribution, are decreased for linear distribution and are insensitive for uniform distribution.