Influence of meridional shaping on the collapse strength of FRP domes

Parabolic and cubic splines together with circular arcs are used to approximate the meridonal shapes of multisegmental, axisymmetric, externally pressurized domes. Bifurcation buckling, axisymmetric collapse and fibre first ply failure are considered as possible mechanisms of dome collapse. The objective is to maximize the lowest collapse pressure for a constant wall thickness, given the material and the through thickness lamination sequence. The optimization procedure is based on the complex method of Box and the geometrically nonlinear analysis uses the classical lamination theory. The largest increase in the failure load is obtained for segments made out of circular arcs. A generalized ellipse is also used as a possible meridional profile.