The buckling of plastic oblate hemi-ellipsoidal dome shells under externalhydrostatic pressure

The paper presents a theoretical and an experimental investigation into the buckling of seven oblate hemi-ellipsoidal dome shells under external hydro static pressure. Four of the shells were made in glass reinforced plastic a nd three were made from a thermosetting plastic called solid urethane plast ic. All the vessels were tested to destruction. The theoretical study was m ade with the aid of a non-linear finite element solution, where both geomet rical and material non-linearity were allowed for. Good agreement was found between experiment and theory for all the vessels. The very oblate domes f ailed axisymmetrically. Theoretical convergence was good for the more oblat e domes but it was not as good as for the less oblate domes. This may have been because the less oblate domes did not fail in a classical axisymmetric manner as was expected. This work is of much importance in ocean engineeri ng. (C) 2001 Elsevier Science Ltd. All rights reserved.