Nonlinear buckling and postbuckling behaviors of porous FG-GPLRC cylindrical shells with stiffeners subjected to external pressure

The nonlinear buckling behaviors of porous functionally graded graphene platelet-reinforced composite (porous FG-GPLRC) cylindrical shells with stiffeners subjected to external pressure are presented in this paper. Three distribution types of porosity in the shells are considered. The smeared stiffener technique is employed to model the buckling behaviors of the stiffeners. The mechanical formulations are established by the Donnell shell theory with large deflection nonlinearities, and the Ritz method is applied for three deflection amplitudes. The postbuckling expressions of the load-maximal deflection and the explicit critical buckling pressures can be achieved. The numerical investigations indicate the outstanding effects of stiffeners, porosity distribution, porosity coefficient, and graphene platelet (GPL) mass fraction on the nonlinear buckling responses of the stiffened shells.