A new analytical approach to the nonlinear thermo-mechanical buckling behavior of three-dimensional graphene foams reinforced complexly curved caps and circular plates

For the first time, the nonlinear buckling responses of shallow complex curved caps and circular plates made from three-dimensional graphene foams reinforced composite (3DGF-RC) subjected to uniformly distributed pressure and thermal loads are presented and analyzed. The four curvature types of complexly curved caps are considered to be spherical, parabolic, ellipsoid, and sinusoid caps. The governing formulations are established using the first-order shear deformation theory (FSDT) and the von Kármán geometrical nonlinearities. The trigonometric solution forms of deflection and rotation angle are proposed. The equilibrium equations in the nonlinear algebraic forms are obtained approximately by applying the Galerkin method. The results are flexibly applied to 3DGF-RC caps with complex curved shell designs in engineering. From the investigated results, it is possible to evaluate the nonlinear thermal and mechanical buckling responses of 3DGF-RC complexly curved caps and circular plates with different geometrical and material input parameters. Some useful remarks on the nonlinear buckling responses of the considered types of caps and plates can be recognized from the numerical examples. Especially, the advantage of the sinusoid caps in terms of thermal and mechanical postbuckling load-carrying capacity can be clearly observed in most investigated cases.