Nonlinear Buckling Behavior of FG-CNTRC Toroidal Shell Segments Stiffened by FG-CNTRC Stiffeners Under External Pressure

Abstract

An analytical approach of nonlinear buckling and postbuckling analysis of functionally graded carbon nanotubes reinforced composite (FG-CNTRC) toroidal shell segments stiffened by ring or stringer FG-CNTRC stiffeners under external pressure is presented in the present study. A novel smeared stiffener technique is developed for FG-CNTRC stiffeners. The nonlinear stability equation system of toroidal shell segments is formulated by using the Donnell thin shell theory with the von Kármán geometrical nonlinearities. By introducing the stress function, choosing the three-term solution of deflection, and applying the Galerkin method, the nonlinear postbuckling relation expression can be obtained. Numerical results validate the effects of volume fraction of carbon nanotube, FG-CNTRC stiffeners, the law of carbon nanotube distribution of toroidal shell segment and the FG-CNTRC stiffeners with various geometrical parameters on the nonlinear buckling and postbuckling behaviors of stiffened toroidal shell segments.