Plastic Collapse and the Controlling Failure Pressures of Thin 2:1 Ellipsoidal Shells Subjected to Internal Pressure

In the first part of the paper, plastic collapse pressures of thin 2:1 ellipsoidal shells are determined. The effects of E, σ_yp and strain hardening, S, on the collapse pressure are presented and discussed. The second part of the paper is concerned with the controlling failure pressures of internally pressurized 2:1 ellipsoidal shells. This involves the consideration of both plastic collapse pressures and asymmetric buckling pressures (the latter were obtained from a companion paper). Curves of the controlling failure pressures versus D/t are given for several values of σ_yp and S. Both aluminum and steel shells are considered. Dimensionless buckling and collapse pressures are also tabulated and some very simple formulas for both failure modes are suggested which should be useful to designers.