Postbuckling of sandwich plates with nanotube-reinforced composite face sheets resting on elastic foundations

This paper investigates compressive postbuckling under thermal environments and thermal postbuckling due to a uniform temperature rise are presented of a sandwich plate with carbon nanotube-reinforced composite (CNTRC) face sheets resting on an elastic foundation. The material properties of CNTRC face sheets are assumed to be graded in the thickness direction, and are estimated through a micromechanical model. The governing equations of the plate are based on a higher-order shear deformation plate theory that includes plate-foundation interaction. The thermal effects are also included and the material properties of both CNTRC face sheets and homogeneous core layer are assumed to be temperature-dependent. A two-step perturbation technique is employed to determine buckling loads (temperature) and postbuckling equilibrium paths. The numerical illustrations concern the compressive and thermal postbuckling behavior of perfect and imperfect, sandwich plates with functionally graded CNTRC face sheets resting on Pasternak elastic foundations under different thermal environmental conditions, from which results for the sandwich plate with uniformly distributed CNTRC face sheets are also obtained for comparison purposes. The results reveal that the foundation stiffness, the temperature changes, the nanotube volume fraction of face sheet, and the core-to-face sheet thickness ratio have significant effects on the compressive buckling load and postbuckling behavior of the sandwich plate, whereas this effect on the thermal postbuckling behavior is less pronounced for the same sandwich plate.

► We extend the concept of functionally graded materials to the sandwich plates with CNTRC face sheets. ► We propose a multi-scale approach for postbuckling analysis of sandwich plates with CNTRC face sheets. ► Nanotube volume fraction has a significant effect on the compressive buckling of the plate. ► The core-to-face sheet thickness ratio has a significant effect on the compressive buckling of the plate. ► These effects are less pronounced on the thermal buckling of the same plate.