Static Bending, Vibration, and Buckling Responses of a Sandwich Beam Composed of Five Layers Considering Honeycomb Core and CNTRC with SMA Particles and Temperature-Dependent Material Properties Using SSDT

The novelty and main contributions of this research are to investigate simultaneously static bending, free vibration, and buckling responses of a sandwich beam composed of a five-layer beam using sinusoidal shear deformation theory (SSDT). In this work, five layers of a sandwich beam including a honeycomb core, carbon nanotubes reinforced composite (Matrix and Resin) (CNTRC) at the top and bottom of the core, and also, shape memory alloy (SMA) in the form of nanoscale particles with matrix in top and bottom of CNTRC are derived. In this study, the governing equations of equilibrium are obtained using the principle of minimum potential energy for deflection and buckling analyses, while Hamilton's principle is employed to obtain the governing equations of motion. Then, based on Navier's type method for simply supported boundary conditions, the deflection, critical buckling load, and the natural frequency for a sandwich beam composed of five layers are obtained. To validate the results, they are compared with existing literature, and there is a good agreement between them. Also, the effects of the thickness of the core, volume fraction of carbon nanotubes, and volume fraction of SMA are analyzed. The results reveal that changing the volume fraction from 0 to 0.01 results in a 30% decrease in deflection. It is concluded that with an enhancement in thickness ratio, the heat flux decreases due to the increase in the thickness of the core, while the thickness of face sheets decreases because the conductivity coefficient for CNT is higher than the core. Moreover, increasing temperature softens the material, leading to a decrease in the critical buckling load.