A New Analytical Approach for Nonlinear Global Buckling of Axially Compressed and Tensiled Sandwich Toroidal Shell Segments with CNTRC Coatings and Corrugated Core in Thermal Environment

In this paper, the nonlinear global buckling and postbuckling responses of axially compressed and tensiled sandwich toroidal shell segments with functionally graded carbon nanotube-reinforced composite (FG-CNTRC) coatings and corrugated core in the thermal environment are investigated. Three distributed types of FG-CNTRC coatings with two geometrical types of corrugated core, and three shell types including convex, concave, and cylindrical shells are considered. By adding the thermal forces to the governing equations, a homogenization model for corrugated structures is developed to simulate the thermal and mechanical behavior of the trapezoidal and round corrugated core. The potential energy expression of sandwich shells is established according to the Donnell shell theory with the nonlinearities of deflection, an algorithm to solve the governing equation is developed using the Ritz energy method, and three equilibrium equations are obtained respecting three amplitudes of deflection. The axial critical buckling loads and postbuckling curves of shells can be achieved after some calculations. The numerical examples prove the beneficial effects of corrugated core and CNTRC coatings on nonlinear global buckling responses of sandwich toroidal shell segments significantly.