Postbuckling of pressure-loaded auxetic sandwich cylindrical shells with FG-GRC facesheets and 3D double-V meta-lattice core

The sandwich cylindrical shells with auxetic 3D double-V meta-lattice core and graphene-reinforced composite (GRC) facesheets are designed, modeled and analyzed to predict their postbuckling behaviors under external pressure. The 3D double-V meta-lattices, developed form the 2D double arrowed honeycombs, are designed that can be self-adapted to meet the requirements of the curvature variation of sandwich cylindrical shells. By means of micromechanical modeling according to the extended Halpin-Tsai model, the material properties are determined for GRC facesheets. Moreover, with the consideration of thermal environments, all the material properties are taken to be temperature-dependent. The GRC facesheets are further designed to have different distributions of graphene sheets along the shell radial direction, to make the sandwich cylindrical shells possess functionally graded (FG) configurations, which has a distinct influence on the buckling and postbuckling behaviors, as demonstrated by numerical results from full-scale FE simulations. The effects of thermal environments, strut radii, shell lengths and curvature radii are also discussed in detail.