Scale-Dependent Buckling Analysis of Advanced Lightweight Nanocomposite Sandwich Beams Regarding Shear Deformation and Temperature Changes Effects

In this study, the mechanical buckling of a Timoshenko sandwich microbeam is analysed, where the core is made of functionally graded porous materials, and the facesheets are composed of graphene platelets reinforced nanocomposites. The mechanical properties of the beam layers vary along the thickness direction based on defined functions, and the microstructure is subjected to thermal load. The governing equations are derived using the principle of virtual work and the variational method based on both first-order shear deformation and modified couple stress theories to capture the effect of shear deformation and scale. Navier's method is employed as an analytical solution for simply supported boundary conditions to obtain the critical buckling loads of the microbeam. The effects of various factors such as temperature changes, porosity coefficient, amount and dispersion type of reinforcing nanoparticles in the facesheets, elastic foundation parameters, and other important parameters are