Energy barrier as a criterion for stability estimation of spherical shell under uniform external pressure

Energy perturbation is applied as a measure in the stability analysis of a spherical shell subjected to uniform external pressure. The energy barrier (buckling energy) is calculated using asymptotic method, which allows to estimate sensitivity of the structure to the perturbation. It is possible to define the level of external pressure separating areas of small and extensive sensitivity of the structure to the perturbations. This pressure level can be recommended as a design buckling load for spherical caps. The obtained result corrects NASA SP-8032 recommendations which are over-conservative. The asymptotic approach is validated using ANSYS software package. In addition, the influence of boundary conditions on buckling load is estimated using the software.