Buckling of edge-damaged filament-wound composite cylindrical shells under combined torsional/axial loads

The stability of filament-wound composite cylindrical shells under combined torsional/axial loading is considered, for the case in which edge-damage is present at one end of the cylinders. The displacement equilibrium equations, based on Flügge's quasi-linear theory, are solved using a finite complex Fourier transform together with the introduction of a displacement function. The zero of a determinantal equation, arising from nontrivial fulfilment of the boundary conditions, furnishes the value of the critical torque/axial load. The edge-damage is modelled by nonuniform boundary conditions. Results indicated that for isotropic shells the degree of sensitivity to edge-damage decreased the lower the applied axial load, irrespective of the direction of the applied torque. However, for anisotropic shells certain torques can actually enhance the critical axial load sustainable. This effect persists in the presence of edge-damage, and, in addition, can desensitize the shell to edge-damage over a larger section of its circumference.