Buckling of externally pressurized steel toriconical shells

• Rare test data.
• Buckling strength versus geometry.
• Imperfection sensitivity.

The inclusion of toroidal (knuckle) segment between cylinder and conical vessel end closure is a natural way for diffusing the stress jump at the junction. But there is very little experimental data in support of the knuckle’s role and its influence. Hence eight steel toriconical shells have been buckled by quasi-static external pressure in order to measure this problem. Diameter of all models was 200 mm at the base and their wall thickness was 2 mm. The apex semi-angle was 45 deg for all shells. Experimental buckling pressures varied from 3.9 MPa to 4.4 MPa despite large variations in shape. Comparisons of experimental failure pressures with numerical predictions based on several approaches to modelisation are given. The latter are based on axisymmetric modelling as well as on measured geometry and wall thickness. The ratio of experimental to numerical failure loads varies from 1.05 to 1.16.