Minimum sensitivity design of laminated shells under axial load and external pressure

A laminated cylindrical shell of finite length under combined loads is optimized for minimum sensitivity of buckling load to variations in ply angles subject to a constraint on buckling load. The design variable is taken as the fiber orientation of individual layers. The general theory of laminated plates is employed to determine the buckling loads. The formulation includes the contribution of the shear deformation and the variation of the radius over the thickness of the shell. Numerical results are given for both thin and thick shells. The results are given for various values of the external pressure and different shell aspect ratios. It is shown that the minimum sensitivity design depends on the constraint on buckling load.