Buckling analysis of clamped circular cylindrical shells subjected to combined compression and circumferential pressure loading are investigated using a finite element method. A systematic procedure for the formulation of the problem is based upon the criterion that the condition for neutral stability of a system is the vanishing of the second variation of the total potential energy from the stable equilibrium state to the perturbed bifurcation state.
The orthotropy of the fiber-reinforced laminate leads to coupling stiffness between forces and changes in curvature as well as between moments and in-surface strains. These coupling stiffnesses do not occur for isotropic shells. The effects of coupling stiffnesses are evaluated for various fiber orientations and stacking sequences of composite laminated cylindrical shells. It is shown that the buckling loads are decreased as the coupling stiffnesses increase, and this effect is more important for lateral pressure buckling loads than for axial buckling loads.
