Buckling of Externally Pressurized Toroidal Vessels with Circular-Elliptical Cross-Section

Abstract

Buckling is a prominent failure mode of thin-walled structures,
and its information is very crucial. This is readily available for a
complete toroidal shell with circular cross-section - a traditional
toroid - which has been well-researched through analytical and
numerical approaches due to their relatively non-complicated
cross-sectional profile. On the other hand, information about the
buckling of non-conventional toroids is rare, owing to the
associated difficulties in the analytical investigation approaches.
Hence, numerical methods are nowadays usually employed for
studies on these shell types. This is adopted in the present paper
to investigate the buckling behaviour of a circular-elliptical
toroidal shell under external pressure. The vessel consists of a top
semi-circular toroidal segment that is joined tangentially to a
bottom semi-elliptical segment at their equatorial circles of
latitude within the inner and outer regions of the toroidal vessel.
The results from the numerical model were validated through
extreme cases with available data in the literature. It is shown that
circular-elliptical toroidal vessels have a stable post-buckling
behaviour and may be able to resist further load beyond the elastic
bifurcation load. A parametric study was also conducted,
revealing more insights into the buckling response of the vessel.