Buckling of imperfect elastic elliptic toroidal shells subjected to uniform external pressure

Abstract

The effects of axisymmetric initial geometric imperfections on the buckling pressures of externally pressurized steel elastic toroidal shells of elliptical cross-section are studied in this paper. The shapes of the axisymmetric localized imperfections are increased-radius circular ‘flat spots’ and smooth dimples. In most cases, the locations of the imperfections are at the north (Φ = 180°) and south (Φ = 0°) poles of the cross-section. The main shells investigated are prolate ellipses having k(≡ a/ b) = 1.5, R/ b = 4 and 10 and b/ t = 50, 100 and 500. Some studies of shells with k = 2.0 and 2.5 and k = 0.833 (an oblate ellipse) are also included.