A semi-analytical model for buckling and stress analyses of pressurized composite cylinders

Circular Cylindrical shells structures play an important role, mainly in the aerospace sectors. In general, they are subjected to external loads and internal pressure due to internal storage such as a propulsion fuel. In this work, a semi-analytical model using Ritz method is proposed to evaluate the axial critical buckling load and internal pressure behaviour of composite cylindrical shells. Simulations were performed for different laminate stacking sequences based on unidirectional tape carbon/epoxy. Conditions of simple support and clamped edges are evaluated. The model consists of using trigonometric functions to approximate the displacement field in the Ritz formulation. In this case, the functions are chosen to meet the geometrical boundary conditions and a suitable number of terms in the Ritz method are chosen to achieve convergence results. The Ritz method formulation is based on the total potential energy and the Reissner-Mindlin hypothesis is also considered in the strain-displacement relationships for buckling cases. The critical buckling loads and buckling modes are obtained from the resultant eigenproblem when the total potential energy is minimized. The results are compared with numerical predictions obtained using the commercial software Abaqus, based on finite element method (FEM) and results available in the literature.